标签:style blog color os io for ar div
就是看无向图有几个连通块,答案就是2n-num。
范围很小,就用矩阵来存图减少代码量。
#include<iostream> #include<cstdio> #include<cstdlib> #include<cstring> #include<cmath> #include<map> #include<set> #include<vector> #include<algorithm> #include<stack> #include<queue> using namespace std; #define INF 1000000000 #define eps 1e-8 #define pii pair<int,int> #define LL long long int int n,m,maps[55][55],a,b; int mark[55],num; void dfs(int x) { mark[x]=1; for(int i=1;i<=n;i++) { if(mark[i]==0&&maps[x][i]) { dfs(i); } } } int main() { //freopen("in1.txt","r",stdin); //freopen("out.txt","w",stdout); scanf("%d%d",&n,&m); for(int i=1;i<=m;i++) { scanf("%d%d",&a,&b); maps[a][b]=maps[b][a]=1; } for(int i=1;i<=n;i++) { if(!mark[i]) { num++; dfs(i); } } printf("%I64d\n",(LL)1<<(n-num)); //fclose(stdin); //fclose(stdout); return 0; }
Codeforces Round #254(div2)B,布布扣,bubuko.com
标签:style blog color os io for ar div
原文地址:http://www.cnblogs.com/zywscq/p/3921094.html