![\"\u5728\u8fd9\u91cc\u63d2\u5165\u56fe\u7247\u63cf\u8ff0\"](\"https:\/\/img-blog.csdnimg.cn\/20210419141856810.png?x-oss-process=image\/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI5MzUzMDgz,size_16,color_FFFFFF,t_70\")
\u7b54\u6848<\/strong>\uff1a3181<\/p>\n\n\n\n
#include <iostream>\n\nusing namespace std;\n\nconst int N=100;\n\nint n;\nint st[N];\n\nint split(int n)\n{\n while(n)\n {\n if(--st[n%10]<0) return false;\n n\/=10;\n }\n return true;\n}\n\nint main()\n{\n n=2021;\n for(int i=0;i<10;i++) st[i]=n;\n\n int i=1;\n while(split(i)) i++;\n\n cout<<i-1<<endl;\n\n return 0;\n}<\/code><\/pre>\n\n\n\nB\uff1a\u76f4\u7ebf<\/h3>\n\n\n\n
\u9898\u76ee<\/strong>
![\"\u5728\u8fd9\u91cc\u63d2\u5165\u56fe\u7247\u63cf\u8ff0\"](\"https:\/\/img-blog.csdnimg.cn\/20210419142108299.png?x-oss-process=image\/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI5MzUzMDgz,size_16,color_FFFFFF,t_70\")
\u9898\u89e3<\/strong><\/p>\n\n\n\n\n- \u5e38\u89c4\u601d\u8def\u7528\u659c\u7387\uff0c\u4f46\u8fd9\u91cc\u659c\u7387\u76f8\u540c\u7684\u53ef\u80fd\u4e5f\u662f\u4e0d\u540c\u7684\u76f4\u7ebf\uff0c\u7531\u6b64\u6211\u4eec\u53ef\u4ee5\u5b58\u4e00\u4e0b\u8be5\u659c\u7387\u5728 y \u8f74\u4e0a\u7684\u622a\u8ddd\uff0c\u5c31\u80fd\u552f\u4e00\u5224\u65ad\u4e86<\/li>\n\n\n\n
- \u7279\u6b8a\u5904\u7406 $x1-x2=0$ \u7684\u70b9\uff08\u659c\u7387\u4e3a\u65e0\u7a77\uff09\uff1a\u76f4\u63a5\u52a0\u4e0a\u7ad6\u7ebf\u6761\u6570\u5373\u53ef<\/li>\n\n\n\n
- \u4e5f\u53ef\u4ee5\u5148\u5f04\u51fa\u6240\u6709\u76f4\u7ebf\uff0c\u6392\u4e2a\u5e8f\u65b9\u4fbf\u53bb\u91cd\u4e00\u4e9b\uff0c\u8fd9\u91cc\u5c31\u4e0d\u5199\u4e86<\/li>\n<\/ul>\n\n\n\n
\u7b54\u6848<\/strong>\uff1a 40257<\/p>\n\n\n\n#include <iostream>\n#include <cmath>\n\nusing namespace std;\n\nconst int N=1000010;\nconst double eps=1e-6;\n\nint n,m;\ndouble st[N],d[N];\nint cnt;\n\nbool check(double k,double t)\n{\n for(int i=0;i<cnt;i++)\n {\n if(abs(st[i]-k)<eps&&abs(d[i]-t)<eps) return false;\n }\n d[cnt]=t;\n st[cnt++]=k;\n return true;\n}\n\nint main()\n{\n \/\/n=20,m=21;\n \/\/n=3,m=4; \/\/35\n \/\/n=2,m=3; \/\/11\n cin>>n;\n m=n+1;\n\n int res=0;\n for(int x1=0;x1<n;x1++)\n for(int y1=0;y1<m;y1++)\n for(int x2=0;x2<n;x2++)\n for(int y2=0;y2<m;y2++)\n {\n if(x1==x2) continue;\n double dx=x1-x2,dy=y1-y2;\n double k=dy\/dx;\n if(check(k,y1-k*x1)) res++;\n }\n cout<<res+n<<endl;\n return 0;\n}<\/code><\/pre>\n\n\n\nC\uff1a\u8d27\u7269\u6446\u653e<\/h3>\n\n\n\n
![\"\u5728\u8fd9\u91cc\u63d2\u5165\u56fe\u7247\u63cf\u8ff0\"](\"https:\/\/img-blog.csdnimg.cn\/20210419154103773.png?x-oss-process=image\/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI5MzUzMDgz,size_16,color_FFFFFF,t_70\")
\u7b54\u6848<\/strong>\uff1a2430<\/p>\n\n\n\n\u7b97\u6cd51\uff1a<\/strong> \u679a\u4e3e\u7ea6\u6570\u6cd5\uff0c\u56e0\u4e3a\u4e58\u79ef\u7b49\u4e8e n \u53ea\u53ef\u80fd\u662f n \u7684\u7ea6\u6570\uff0c\u56e0\u6b64\u6211\u4eec\u53ef\u4ee5\u5148\u9884\u5904\u7406\u51fa\u6240\u6709\u7684\u7ea6\u6570\uff0c\u6700\u540e n^3 \u679a\u4e3e\u5373\u53ef\uff08\u53ea\u6709128\u4e2a\u7ea6\u6570\uff09<\/p>\n\n\n\n#include <iostream>\n#include <vector>\n\nusing namespace std;\n\ntypedef long long LL;\n\nLL n;\n\nint main()\n{\n n=2021041820210418;\n vector<LL> a;\n\n for(LL i=1;i*i<=n;i++)\n {\n if(n%i==0)\n {\n a.push_back(i);\n a.push_back(n\/i);\n }\n }\n\n int res=0;\n for(auto i:a)\n for(auto j:a)\n for(auto k:a)\n if(i*j*k==n) res++;\n\n cout<<res<<endl;\n\n return 0;\n}<\/code><\/pre>\n\n\n\n\u7b97\u6cd52\uff1a<\/strong> \u76f4\u63a5\u66b4\u529b\u6cd5\uff08\u4e5f\u5c314s\u800c\u5df2\uff09<\/p>\n\n\n\n#include <iostream>\n\nusing namespace std;\n\ntypedef long long LL;\n\nLL n;\n\nint main()\n{\n n=2021041820210418;\n\n int res=0;\n for(LL i=1;i*i*i<=n;i++)\n if(n%i==0)\n for(LL j=i;i*j*j<=n;j++) \/\/j=i\u5f00\u59cb\uff0c\u4fdd\u6301\u9012\u589e\n if(n\/i%j==0)\n {\n LL k=n\/i\/j;\n if(i==j&&i==k) res++;\n else if(i==j||i==k||j==k) res+=3;\n else res+=6;\n }\n\n cout<<res<<endl;\n\n return 0;\n}<\/code><\/pre>\n\n\n\n\u7b97\u6cd53\uff1a<\/strong> \u7b5b\u8d28\u56e0\u5b50+\u624b\u7b97\u6392\u5217\u7ec4\u5408\u6bd4\u8f83\u5feb\uff0c\u4e5f\u53ef\u4ee5 dfs\uff0c\u4f46\u662f\u8981\u5904\u7406\u4e00\u4e0b\u91cd\u590d<\/p>\n\n\n\n\u7b5b\u8d28\u56e0\u5b50\u4ee3\u7801\u5c31\u4e0d\u5c55\u793a\u4e86\n\u8d28\u56e0\u5b50\u53ca\u4e2a\u6570\u5982\u4e0b\uff1a\n5882353 1\n2857 1\n131 1\n2 1\n17 1\n3 3<\/code><\/pre>\n\n\n\n
\n\n\n\nD\uff1a\u8def\u5f84<\/h3>\n\n\n\n
![\"\u5728\u8fd9\u91cc\u63d2\u5165\u56fe\u7247\u63cf\u8ff0\"](\"https:\/\/img-blog.csdnimg.cn\/20210419152337575.png?x-oss-process=image\/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI5MzUzMDgz,size_16,color_FFFFFF,t_70\")
\u9898\u89e3<\/strong>
\u77e5\u8bc6\u70b9\uff1a\u6700\u77ed\u8def\uff0cdijkstra<\/p>\n\n\n\n\n- \u6700\u77ed\u8def\u95ee\u9898\uff0c\u6d89\u53ca\u5230\u6c42\u6700\u5c0f\u516c\u500d\u6570 $lcm(a,b)=a*b\/gcd(a,b)$<\/li>\n\n\n\n
- \u542c\u4e00\u4e9b\u5927\u4f6c\u8bf4dp\u4e5f\u53ef\u4ee5\uff0c\u4f46\u662f\u4e0d\u6e05\u695a\u6b63\u786e\u6027\uff0c\u5373\u662f\u5426\u4e00\u5b9a\u4ece\u524d\u5f80\u540e\u8d70\u3002<\/li>\n\n\n\n
- \u7531\u4e8e\u672c\u9898\u6570\u636e\u8303\u56f4\u5f88\u5c0f\u52a0\u4e0a\u662f\u586b\u7a7a\u9898\uff0c\u76f4\u63a5\u6700\u66b4\u529b\u7684 $O(n^2)$ \u8fea\u6770\u5373\u53ef\u3002\u5982\u679c\u8fb9\u8fc7\u591a\u6216\u8005 n^2 \u8d85\u65f6\u53ef\u4ee5\u8003\u8651\u5806\u4f18\u5316\u8fea\u6770<\/li>\n<\/ul>\n\n\n\n
\u7b54\u6848<\/strong>\uff1a10266837<\/p>\n\n\n\n#include <iostream>\n#include <cstring>\n\nusing namespace std;\n\nconst int N=2050;\n\nint g[N][N],n;\nbool st[N];\nint dis[N];\n\nint gcd(int a,int b)\n{\n return b?gcd(b,a%b):a;\n}\n\nvoid djs()\n{\n memset(dis,0x3f,sizeof dis);\n dis[1]=0;\n for(int k=0;k<n;k++)\n {\n int u=0;\n for(int i=1;i<=n;i++)\n {\n if(!st[i]&&dis[i]<dis[u]) u=i;\n }\n st[u]=true;\n if(u==2021) break;\n for(int i=1;i<=n;i++) dis[i]=min(dis[i],dis[u]+g[u][i]);\n }\n}\n\nint main()\n{\n n=2021;\n for(int i=1;i<N;i++)\n for(int j=i;j<N;j++)\n {\n if(j-i>21) g[i][j]=g[j][i]=0x3f3f3f3f;\n else g[i][j]=g[j][i]=i*j\/gcd(i,j);\n }\n\n djs();\n\n cout<<dis[n]<<endl;\n\n return 0;\n}<\/code><\/pre>\n\n\n\n
\n\n\n\nE\uff1a\u56de\u8def\u8ba1\u6570<\/h3>\n\n\n\n
![\"\u5728\u8fd9\u91cc\u63d2\u5165\u56fe\u7247\u63cf\u8ff0\"](\"https:\/\/img-blog.csdnimg.cn\/2021041915364242.png?x-oss-process=image\/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI5MzUzMDgz,size_16,color_FFFFFF,t_70\")
\u9898\u89e3<\/strong><\/p>\n\n\n\n\n- \u76f4\u63a5\u7206\u641c\u65f6\u95f4\u590d\u6742\u5ea6\u662f\u9636\u4e58\u7ea7\u522b\u7684\uff0c\u5373 $O(n!)$\uff0c\u5927\u6982\u53ea\u80fd\u641c\u523015\u5c31\u4e0d\u884c\u4e86\uff0c\u539f\u56e0\u5728\u4e8e\u6bcf\u4e2a\u70b9\u641c\u7d22\u987a\u5e8f\u53ef\u4ee5\u4e0d\u4e00\u6837\uff0c\u8fd1\u4f3c\u770b\u6210 n \u7684\u5168\u6392\u5217\u5c31\u662f\u9636\u4e58\u7ea7\u522b\u4e86\u3002<\/li>\n\n\n\n
- \u4ed4\u7ec6\u5206\u6790\u9898\u76ee\u4f1a\u53d1\u73b0\u6bcf\u4e2a\u70b9\u7684\u72b6\u6001\u6211\u4eec\u90fd\u8981\u5904\u7406\u5230\u4f4d\uff0c\u4e14\u8981\u7ecf\u8fc7\u6bcf\u4e2a\u70b9\uff0c20\u662f\u975e\u5e38nice\u7684\u4e00\u4e2a\u6570\u5b57\uff0c\u4f1a\u60f3\u5230\u4ec0\u4e48\uff1a\u72b6\u6001\u538b\u7f29<\/strong>\uff0c\u6211\u4eec\u4e0d\u59a8\u7528 $(1<<21)-1$\u5185\u7684\u6bcf\u4e2a\u6570\u5b57\u6765\u8868\u793a\u6240\u6709\u72b6\u6001\uff0c\u4f46\u662f\u4f1a\u53d1\u73b0\u5982\u679c\u53ea\u8fd9\u6837\u662f\u4e0d\u597d\u5904\u7406\u7684\uff0c\u56e0\u6b64\u518d\u52a0\u5165\u4e00\u7ef4\u3002<\/li>\n\n\n\n
- \u72b6\u6001\u8868\u793a<\/strong>\uff1a$dp[state][j]$ \u8868\u793a\u5f53\u524d\u7ecf\u8fc7\u4e86\u7684\u70b9\u72b6\u6001\u4e3a state \u4e14\u6700\u540e\u4e00\u6b21\u7ecf\u8fc7\u7684\u70b9\u4e3a j \u7684\u65b9\u6848\u6570\u3002<\/li>\n\n\n\n
- \u72b6\u6001\u8f6c\u79fb<\/strong>\uff1a$$dp[state][j]= \\sum_{i=0}^{20}dp[state-2^i][k]$$
\u8f6c\u79fb\u6761\u4ef6<\/strong>\uff1astate \u7684\u7b2c j \u4f4d\u662f 1 \u5e76\u4e14 state \u7684\u7b2c k \u4f4d\u4e5f\u662f 1\uff0c$j!=k\uff0cgcd(i+1,k+1)==1$\u3002<\/li>\n\n\n\n- \u7ed3\u679c\u8868\u793a<\/strong>\uff1a$$res=\\sum_{i=0}^{20}dp[(1<<21)-1][i]$$\u3002\u6709\u7684\u5c0f\u4f19\u4f34\u53ef\u80fd\u4f1a\u95ee\u539f\u56e0\uff1a$dp[(1<<21)-1][i]$ \u8868\u793a\u7684\u662f\u7ecf\u8fc7\u4e86\u6240\u6709\u70b9\u4e14\u6700\u540e\u5728\u7b2c i \u4e2a\u4f4d\u7f6e\u4e0a\u7684\u65b9\u6848\u6570\uff0c\u73b0\u5728\u5e76\u6ca1\u6709\u56de\u5230\u6e90\u70b9\uff0c\u4e5f\u5c31\u662f\u8bf4\u6700\u540e\u7684\u6240\u6709\u7ed3\u5c3e\u70b9\u4e3a i \u7684\u65b9\u6848\u4e2d\u5c31\u662f\u6700\u540e\u5012\u6570\u7b2c2\u4e2a\u70b9\uff0c\u518d\u5f80\u524d\u8d70\u4e00\u6b65\u5c31\u662f\u7ec8\u70b9\uff08\u539f\u70b9\uff09\u4e86\uff0c\u800c\u6700\u540e\u7684\u72b6\u6001\u662f\u7531\u6240\u6709\u5012\u6570\u7b2c2\u7684\u72b6\u6001\u8f6c\u79fb\u8fc7\u6765\uff0c\u6240\u4ee5\u5c06\u6240\u6709 $dp[(1<<21)-1][i]$ \u52a0\u8d77\u6765\u5c31\u662f\u6700\u7ec8\u56de\u5230\u539f\u70b9\u7684\u65b9\u6848\u6570\uff0c\u4e5f\u5c31\u662f\u54c8\u5bc6\u987f\u56de\u8def\u7684\u65b9\u6848\u6570\u3002<\/li>\n<\/ul>\n\n\n\n
\u7b54\u6848<\/strong>\uff1a881012367360<\/p>\n\n\n\n#include <bits\/stdc++.h>\n#define rep(i, l, r) for (int i = l; i <= r; i++)\n\nusing namespace std;\n\nconst int INF=0x3f3f3f3f,MOD=1000000007,P=131,N=22,M=400010;\n\nint n=21;\nlong long dp[1<<21][21];\nbool g[N][N];\n\nint gcd(int a,int b)\n{\n return b?gcd(b,a%b):a;\n}\n\nint main()\n{\n rep(i,1,n)\n rep(j,i+1,n)\n if(gcd(i,j)==1) g[i][j]=g[j][i]=true;\n\n dp[1][0]=1;\n rep(i,2,1<<n)\n rep(j,0,20)\n if(i>>j&1)\n rep(k,0,20)\n if(j!=k&&g[j+1][k+1]&&(i>>k&1))\n dp[i][j]+=dp[i-(1<<j)][k];\n\n long long res=0;\n rep(i,0,20) res+=dp[(1<<21)-1][i];\n\n cout<<res<<endl;\n\n return 0;\n}<\/code><\/pre>\n\n\n\n
\n\n\n\nF\uff1a\u781d\u7801\u79f0\u91cd<\/h3>\n\n\n\n
![\"\u5728\u8fd9\u91cc\u63d2\u5165\u56fe\u7247\u63cf\u8ff0\"](\"https:\/\/img-blog.csdnimg.cn\/20210419231442412.png?x-oss-process=image\/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI5MzUzMDgz,size_16,color_FFFFFF,t_70\")
![\"\u5728\u8fd9\u91cc\u63d2\u5165\u56fe\u7247\u63cf\u8ff0\"](\"https:\/\/img-blog.csdnimg.cn\/20210419231500346.png?x-oss-process=image\/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI5MzUzMDgz,size_16,color_FFFFFF,t_70\")
\u9898\u89e3<\/strong>
dp \u53ef\u4ee5\u505a\uff0c\u679a\u4e3e\u6bcf\u4e00\u4e2a\u781d\u7801\uff0c\u518d\u679a\u4e3e\u6240\u6709\u5df2\u7ecf\u5b58\u5728\u7684\u91cd\u91cf\uff0c\u52a0\u51cf\u5f53\u524d\u91cd\u91cf a[i]<\/code> \u5373\u53ef\uff0c\u590d\u6742\u5ea6 $O(nm)$
\u72b6\u6001\u65b9\u7a0b\uff1a$$t[j]=t[j-a[i]]=true,t[j+a[i]]=true$$ \u7528\u524d\u9762\u8f6e\u7684\u7ed3\u679c\u6807\u8bb0\u8fd9\u4e00\u8f6e\u3002
\u4f17\u6240\u5468\u77e5\uff1a\u4e00\u7ef4\u80af\u5b9a\u5feb\u70b9\uff08\u6eda\u52a8\u6570\u7ec4\uff09
\u4e00\u7ef4\uff1a<\/p>\n\n\n\n#include <iostream>\n#include <cstring>\n\nusing namespace std;\n\nconst int N=110,M=200010,B=M\/2;\n\nint a[N],n;\nbool f[M],t[M];\n\nint main()\n{\n cin>>n;\n int m=0;\n for(int i=1;i<=n;i++) cin>>a[i],m+=a[i];\n\n f[B]=1;\n for(int i=1;i<=n;i++)\n {\n for(int j=-m;j<=m;j++)\n if(f[j+B]) \n {\n t[j+B]=true;\n t[j+a[i]+B]=t[j-a[i]+B]=true;\n }\n memcpy(f,t,sizeof t);\n }\n\n int res=0;\n for(int i=1;i<=m;i++) res+=f[i+B];\n cout<<res<<endl;\n\n return 0;\n}<\/code><\/pre>\n\n\n\n\u4e8c\u7ef4\uff1a<\/p>\n\n\n\n
#include <iostream>\n\nusing namespace std;\n\nconst int N=110,M=200010,B=M\/2;\n\nbool f[N][M];\nint a[N],n;\n\nint main()\n{\n cin>>n;\n int m=0;\n for(int i=1;i<=n;i++) cin>>a[i],m+=a[i];\n\n f[0][B]=1;\n for(int i=1;i<=n;i++)\n {\n for(int j=-m;j<=m;j++)\n {\n if(f[i-1][j+B]) f[i][j+B]=true; \/\/\u4e0d\u9009\n if(f[i-1][j+B])\n f[i][j+a[i]+B]=f[i][j-a[i]+B]=true;\n }\n }\n\n int res=0;\n for(int i=1;i<=m;i++) res+=f[n][i+B];\n cout<<res<<endl;\n\n return 0;\n}<\/code><\/pre>\n\n\n\nG\uff1a\u5f02\u6216\u6570\u5217<\/h3>\n\n\n\n
![\"\u5728\u8fd9\u91cc\u63d2\u5165\u56fe\u7247\u63cf\u8ff0\"](\"https:\/\/img-blog.csdnimg.cn\/20210419231822375.png?x-oss-process=image\/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI5MzUzMDgz,size_16,color_FFFFFF,t_70\")
![\"\u5728\u8fd9\u91cc\u63d2\u5165\u56fe\u7247\u63cf\u8ff0\"](\"https:\/\/img-blog.csdnimg.cn\/20210419231838157.png?x-oss-process=image\/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI5MzUzMDgz,size_16,color_FFFFFF,t_70\")
\u9898\u89e3<\/strong>
\u77e5\u8bc6\u70b9\uff1a\u535a\u5f08\u8bba
\u9996\u5148\u8fd9\u7c7b\u9898\u54b1\u4eec\u81ea\u5df1\u53ef\u4ee5\u6bd4\u5212\u6bd4\u5212\uff0c\u53ef\u4ee5\u627e\u5230\u4e00\u4e9b\u6027\u8d28<\/p>\n\n\n\n\n- \u5982\u679c\u6240\u6709\u6570\u7684\u5f02\u6216\u548c\u4e3a 0\uff0c\u90a3\u4e48\u6240\u6709\u4f4d\u7684\u503c\u90fd\u4e3a\u5076\u6570\uff0c\u6bcf\u4e2a\u6570\u4e0d\u7ba1\u600e\u4e48\u9009\uff0c\u53cc\u65b9\u7684\u6570\u6700\u7ec8\u90fd\u4f1a\u76f8\u7b49\uff0c\u5fc5\u7136\u662f\u5e73\u5c40<\/li>\n\n\n\n
- \u4e0d\u662f\u5e73\u5c40\uff0c\u5fc5\u7136\u5f02\u6216\u548c\u6709\u4e00\u4e2a 1\uff0c\u6211\u4eec\u627e\u5230\u6700\u9ad8\u4f4d\u7684 1\uff0c\u7edf\u8ba1\u6570\u5217\u4e2d\u8fd9\u4f4d\u4e3a 1 \u7684\u6570\u91cf cnt1\uff0c\u5b83\u5fc5\u5b9a\u662f\u5947\u6570\u3002\u5982\u679c\u5982\u679c Alice(\u5148\u624b) \u60f3\u8d62\uff0c\u5fc5\u7136\u8981\u4f7f\u6700\u9ad8\u4f4d\u638c\u63e1\u5728\u81ea\u5df1\u624b\u4e2d\uff0c\u8fd9\u91cc\u8fd8\u6709\u4e00\u4e2a\u70b9\u5c31\u662f\u8fd9\u4e00\u4f4d\u4e3a0\u7684\u5143\u7d20\u6570\u91cf cnt0\uff0c\u5982\u679c\u6253\u4e0d\u8d62\u7684\u65f6\u5019\uff0c\u4f7f\u7528\u8fd9\u4e00\u4f4d\u4e3a 0 \u7684\u6570\u53ef\u4ee5\u4f7f\u5f97\u653b\u9632\u53cd\u8f6c\uff0c\u6700\u7ec8\u6211\u4eec\u8981\u7edf\u8ba1\u7684\u5c31\u662f cnt1+cnt0 \u7684\u6570\u91cf\uff0c\u5982\u679c\u662f\u5947\u6570\uff0c\u5219 Alice \u5fc5\u80dc\uff0c\u53cd\u4e4b Bob \u5fc5\u80dc<\/li>\n\n\n\n
- \u503c\u5f97\u6ce8\u610f\u7684\u6700\u540e\u4e00\u70b9\u5c31\u662f\u5982\u679c\u8be5\u5f02\u6216\u503c\u7684\u6700\u9ad8\u4f4d\u53ea\u6709\u4e00\u4f4d1\uff0c\u90a3\u4e48\u9009\u4e86\u8fd9\u4e2a1\u540e\u65e0\u8bba\u540e\u9762\u600e\u4e48\u9009\u90fd\u662f\u9009\u4e86\u8fd9\u4e2a1\u7684\u6700\u5927\uff0c\u56e0\u6b64\u5982\u679c cnt1=0\uff0c\u5219 Alice \u5fc5\u80dc\uff0c\u8fd9\u4e2a\u60c5\u51b5\u8981\u5148\u5224\u3002<\/li>\n<\/ul>\n\n\n\n
#include <bits\/stdc++.h>\n#define x first\n#define y second\n#define all(x) x.begin(),x.end()\n#define rep(i, l, r) for (int i = l; i <= r; i++)\n#define nep(i, r, l) for (int i = r; i >= l; i--)\nusing namespace std;\ntypedef pair<int,int> PII;\ntypedef pair<pair<int,int>,int> PIII;\ntypedef long long LL;\ntypedef unsigned long long ULL;\nconst int INF=0x3f3f3f3f,MOD=1000000007,P=131,N=200010,M=200010;\n\nint n;\nint w[N];\n\nint main()\n{\n int T; cin>>T;\n while(T--)\n {\n scanf(\"%d\",&n);\n\n int res=0;\n rep(i,1,n)\n {\n scanf(\"%d\",&w[i]);\n res^=w[i];\n }\n if(res==0) puts(\"0\");\n else\n {\n int k=30,cnt1=0,cnt0=0;\n while(!(res>>k&1)) k--;\n rep(i,1,n)\n {\n if(w[i]>>k&1) cnt1++;\n else cnt0++;\n }\n\n if(cnt1==1) puts(\"1\");\n else if(n&1) puts(\"1\");\n else puts(\"-1\");\n }\n }\n\n return 0;\n}<\/code><\/pre>\n\n\n\nH\uff1a\u5de6\u5b69\u5b50\u53f3\u5144\u5f1f<\/h3>\n\n\n\n
![\"\u5728\u8fd9\u91cc\u63d2\u5165\u56fe\u7247\u63cf\u8ff0\"](\"https:\/\/img-blog.csdnimg.cn\/20210421152804922.png?x-oss-process=image\/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI5MzUzMDgz,size_16,color_FFFFFF,t_70\")
![\"\u5728\u8fd9\u91cc\u63d2\u5165\u56fe\u7247\u63cf\u8ff0\"](\"https:\/\/img-blog.csdnimg.cn\/20210421152834801.png?x-oss-process=image\/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI5MzUzMDgz,size_16,color_FFFFFF,t_70\")
![\"\u5728\u8fd9\u91cc\u63d2\u5165\u56fe\u7247\u63cf\u8ff0\"](\"https:\/\/img-blog.csdnimg.cn\/20210421152845530.png\")
\u9898\u89e3<\/strong>
\u77e5\u8bc6\u70b9\uff1a\u6811\u7684\u904d\u5386\uff0c\u6811\u5f62DP
\u8fd9\u9898\u662f\u7ed9\u5b9a\u4e00\u68f5\u6811\uff0c\u95ee\u600e\u4e48\u8f6c\u53ef\u4ee5\u4f7f\u5f97\u6811\u7684\u6df1\u5ea6\u6700\u5927<\/p>\n\n\n\n\n- \u9996\u5148\u5b69\u5b50\u53ef\u4ee5\u4efb\u610f\u9009\uff0c\u90a3\u4e48\u5bf9\u4e8e\u4efb\u610f\u4e00\u4e2a\u6811\u4e0a\u7684\u7ed3\u70b9\uff0c\u6211\u4eec\u627e\u5230\u5b83\u7684\u6240\u6709\u7684\u5b50\u6811\u4e2d\u6700\u6df1\u7684\u4e00\u4e2a\u5b69\u5b50\uff0c\u7136\u540e\u7edf\u8ba1\u5b83\u7684\u5b69\u5b50\u6570\u91cf\uff0c\u628a\u6700\u6df1\u7684\u8fd9\u4e2a\u5b69\u5b50\u7ed3\u70b9\u4f9d\u6b21\u63a5\u5230\u5b83\u6240\u6709\u5b69\u5b50\u540e\u9762\u5c31\u53ef\u4ee5\u4e86\u3002\u4f8b\u5982\uff1a\u6709\u4e09\u4e2a\u5b50\u6811\uff0c\u6df1\u5ea6\u5206\u522b\u662f 2\uff0c3\uff0c4\uff0c\u90a3\u4e48\u6211\u4eec\u7b54\u6848\u5c31\u662f 4+1(\u63a5\u57282\u5b69\u5b50\u4e0a)+1(\u518d\u63a5\u57283\u5b69\u5b50\u4e0a) = 6<\/li>\n<\/ul>\n\n\n\n
#include <bits\/stdc++.h>\n#define x first\n#define y second\n#define all(x) x.begin(),x.end()\n#define rep(i, l, r) for (int i = l; i <= r; i++)\n#define nep(i, r, l) for (int i = r; i >= l; i--)\nusing namespace std;\ntypedef pair<int,int> PII;\ntypedef pair<pair<int,int>,int> PIII;\ntypedef long long LL;\ntypedef unsigned long long ULL;\nconst int INF=0x3f3f3f3f,MOD=1000000007,P=131,N=100010,M=200010;\n\nint n;\nint h[N],e[M],ne[M],idx;\n\nvoid add(int a,int b)\n{\n e[idx]=b,ne[idx]=h[a],h[a]=idx++;\n}\n\nint dfs(int u)\n{\n int cnt=0,maxv=0;\n for(int i=h[u];~i;i=ne[i])\n {\n int j=e[i];\n cnt++;\n maxv=max(maxv,dfs(j));\n }\n\n return maxv+cnt;\n}\n\nint main()\n{\n memset(h,-1,sizeof h);\n cin>>n;\n rep(i,2,n)\n {\n int x; scanf(\"%d\",&x);\n add(x,i);\n }\n\n cout<<dfs(1)<<endl;\n\n return 0;\n}<\/code><\/pre>\n\n\n\nI\uff1a\u62ec\u53f7\u5e8f\u5217<\/h3>\n\n\n\n
![\"\u5728\u8fd9\u91cc\u63d2\u5165\u56fe\u7247\u63cf\u8ff0\"](\"https:\/\/img-blog.csdnimg.cn\/20210421152928697.png?x-oss-process=image\/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI5MzUzMDgz,size_16,color_FFFFFF,t_70\")
![\"\u5728\u8fd9\u91cc\u63d2\u5165\u56fe\u7247\u63cf\u8ff0\"](\"https:\/\/img-blog.csdnimg.cn\/20210421152937897.png\")
\u9898\u89e3<\/strong>
\u8fd9\u9898\u624d\u53d1\u73b0\u662f\u4e2a\u539f\u9898\uff0c\u53ef\u60dc\u5f53\u65f6\u6ca1\u5199\u51fa\u6765<\/p>\n\n\n\n\n- \u5206\u522b\u8ba1\u7b97\u63d2\u5de6\u53f3\u62ec\u53f7\u7684\u65b9\u6848\u6570<\/li>\n\n\n\n
- \u8ba1\u7b97\u53e6\u4e00\u79cd\u62ec\u53f7\u6570\u7684\u65f6\u5019\u76f4\u63a5\u7ffb\u8f6c\u518d\u7ffb\u8f6c\u7b26\u53f7\u5c31\u884c\u4e86<\/li>\n\n\n\n
- \u6700\u540e\u8ba1\u7b97\u603b\u65b9\u6848\u6570\uff0c\u5176\u5b9e\u5c31\u662f\u63d2\u7a7a\u6cd5\uff0c\u5206\u522b\u63d2\u5de6\u53f3\u62ec\u53f7\uff0c\u6700\u540e\u76f8\u4e58\u5373\u53ef<\/li>\n<\/ul>\n\n\n\n
DP\u5206\u6790\uff1a<\/strong>
\u72b6\u6001\u8868\u793a\uff1a<\/strong>$f[i][j]$\uff1a\u53ea\u8003\u8651\u524di\u4e2a\u62ec\u53f7\u5e76\u4e14\u5de6\u62ec\u53f7\u6bd4\u53f3\u62ec\u53f7\u591a $j$ \u7684\u65b9\u6848\u6570
\u72b6\u6001\u8f6c\u79fb\uff1a<\/strong>
\u5f53 s[i]='(‘ \uff0c$f[i][j]=f[i-1][j-1]$;
\u53cd\u4e4b $f[i][j]=f[i-1][j+1]+f[i][j-1]$;\uff08\u63a8\u5bfc\u8fc7\u7a0b\u4e0e\u5b8c\u5168\u80cc\u5305\u7c7b\u4f3c\uff09<\/p>\n\n\n\n\n- \u8fd9\u91cc\u6709\u4e2a\u5c0f\u95ee\u9898\u5c31\u662f\u6709\u53ef\u80fd\u6700\u7ec8\u7684\u7b54\u6848\u521a\u597d\u53d6\u6a21\u540e =0 \u9020\u6210\u8fd4\u56de\u503c\u9519\u8bef\uff0c\u4f46\u662f\u8fd9\u79cd\u60c5\u51b5\u5341\u5206\u7f55\u89c1\uff0c\u53ef\u4ee5\u5ffd\u7565\u4e0d\u8ba1\uff0c\u4e5f\u53ef\u4ee5\u5728\u5b98\u7f51\u901a\u8fc7\uff0c\u5982\u679c\u8981\u907f\u514d\u8fd9\u79cd\u60c5\u51b5\u53ef\u4ee5\u53c2\u8003\u4ee3\u78012<\/strong>\uff0c\u901a\u8fc7\u8ba1\u7b97\u6700\u5c11\u9700\u8981\u6dfb\u52a0\u7684\u62ec\u53f7\u6570 cnt\uff0c\u7136\u540e\u518d\u8ba1\u7b97\u51fa\u7b54\u6848\u662f\u9700\u8981\u8fd4\u56de\u51e0<\/li>\n<\/ul>\n\n\n\n
#include <iostream>\n#include <algorithm>\n#include <cstring>\n\nusing namespace std;\n\ntypedef long long LL;\n\nconst int N=5010,MOD=1e9+7;\n\nLL f[N][N];\nint n;\nchar s[N];\n\nLL get()\n{\n memset(f,0,sizeof f);\n f[0][0]=1;\n for(int i=1;i<=n;i++)\n {\n if(s[i]=='(')\n {\n for(int j=1;j<=n;j++)\n f[i][j]=f[i-1][j-1];\n }\n else\n {\n f[i][0]=(f[i-1][1]+f[i-1][0])%MOD;\n for(int j=1;j<=n;j++)\n f[i][j]=(f[i-1][j+1]+f[i][j-1])%MOD;\n }\n }\n for(int i=0;i<=n;i++)\n if(f[n][i]) return f[n][i];\n return -1;\n}\n\nint main()\n{\n scanf(\"%s\",s+1);\n n=strlen(s+1);\n\n LL a=get();\n\n reverse(s+1,s+n+1);\n for(int i=1;i<=n;i++)\n if(s[i]=='(') s[i]=')';\n else s[i]='(';\n\n LL b=get();\n\n cout<<a*b%MOD<<endl;\n\n return 0;\n}<\/code><\/pre>\n\n\n\n\u4ee3\u78012\uff1a<\/p>\n\n\n\n
#include <bits\/stdc++.h>\nusing namespace std;\ntypedef long long LL;\nconst int INF=0x3f3f3f3f,MOD=1000000007,P=131,N=5010,M=2*N;\n\nchar s[N]; \nint n;\nLL f[N][N];\n\nLL calc()\n{\n int cnt=0, k=0, l=0, r=0;\n for(int i=1;i<=n;i++)\n {\n if(s[i]==')') \n {\n r++, k++;\n if(k>0) k=0,cnt++;\n }\n else l++,k--;\n }\n\n memset(f,0,sizeof f);\n f[0][0]=1;\n for(int i=1;i<=n;i++)\n {\n if(s[i]=='(') \n {\n for(int j=1;j<=n;j++)\n f[i][j]=f[i-1][j-1];\n }\n else\n {\n f[i][0]=(f[i-1][1]+f[i-1][0])%MOD;\n for(int j=1;j<=n;j++)\n f[i][j]=(f[i-1][j+1]+f[i][j-1])%MOD;\n }\n }\n\n return f[n][cnt+l-r]; \/\/\u76f4\u63a5\u8fd4\u56de\u7b54\u6848\n}\n\nint main()\n{\n scanf(\"%s\",s+1);\n n=strlen(s+1);\n\n LL l=calc();\n reverse(s+1,s+n+1);\n for(int i=1;i<=n;i++) \n if(s[i]==')') s[i]='(';\n else s[i]=')';\n\n LL r=calc();\n cout<<l*r%MOD<<endl;\n\n return 0;\n}<\/code><\/pre>\n\n\n\nJ\uff1a\u5206\u679c\u679c\uff08\u9898\u76ee\uff09<\/h3>\n\n\n\n![\"\u5728\u8fd9\u91cc\u63d2\u5165\u56fe\u7247\u63cf\u8ff0\"\/](\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\")
<\/div><\/figure>\n\n\n\n<\/div><\/figure>\n\n\n\n<\/div><\/figure>\n\n\n\n\u540e\u7eed\u5f85\u5b98\u7f51\u9898\u66f4\u65b0\u540e\u518d\u66f4\u65b0\u2026\u5fc3\u6001\u7206\u70b8<\/p>\n","protected":false},"excerpt":{"rendered":"
A\uff1a\u5361\u7247 \u9898\u76ee\u7b54\u6848\uff1a3181 B\uff1a\u76f4\u7ebf \u9898\u76ee\u9898\u89e3 \u7b54\u6848\uff1a 40257 C\uff1a\u8d27\u7269\u6446\u653e \u7b54\u6848\uff1a2430 \u7b97\u6cd51\uff1a […]<\/p>\n","protected":false},"author":1,"featured_media":192,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10],"tags":[44,45,47,48,46,43],"class_list":["post-44","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-lanqiao","tag-c","tag-45","tag-47","tag-48","tag-46","tag-43"],"_links":{"self":[{"href":"https:\/\/www.vcoco.top\/index.php\/wp-json\/wp\/v2\/posts\/44","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vcoco.top\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vcoco.top\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vcoco.top\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vcoco.top\/index.php\/wp-json\/wp\/v2\/comments?post=44"}],"version-history":[{"count":7,"href":"https:\/\/www.vcoco.top\/index.php\/wp-json\/wp\/v2\/posts\/44\/revisions"}],"predecessor-version":[{"id":194,"href":"https:\/\/www.vcoco.top\/index.php\/wp-json\/wp\/v2\/posts\/44\/revisions\/194"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.vcoco.top\/index.php\/wp-json\/wp\/v2\/media\/192"}],"wp:attachment":[{"href":"https:\/\/www.vcoco.top\/index.php\/wp-json\/wp\/v2\/media?parent=44"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vcoco.top\/index.php\/wp-json\/wp\/v2\/categories?post=44"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vcoco.top\/index.php\/wp-json\/wp\/v2\/tags?post=44"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
![\"\u5728\u8fd9\u91cc\u63d2\u5165\u56fe\u7247\u63cf\u8ff0\"\/](\"https:\/\/img-blog.csdnimg.cn\/20210421153003518.png?x-oss-process=image\/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI5MzUzMDgz,size_16,color_FFFFFF,t_70\")
<\/div><\/figure>\n\n\n\n![\"\u5728\u8fd9\u91cc\u63d2\u5165\u56fe\u7247\u63cf\u8ff0\"\/](\"https:\/\/img-blog.csdnimg.cn\/20210421153031618.png?x-oss-process=image\/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI5MzUzMDgz,size_16,color_FFFFFF,t_70\")
<\/div><\/figure>\n\n\n\n![\"\u5728\u8fd9\u91cc\u63d2\u5165\u56fe\u7247\u63cf\u8ff0\"\/](\"https:\/\/img-blog.csdnimg.cn\/2021042115305056.png?x-oss-process=image\/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI5MzUzMDgz,size_16,color_FFFFFF,t_70\")
<\/div><\/figure>\n\n\n\n