1013 Battle Over Cities

Posted 2021-01-03 kkmjy

题意：

思路：计算连通块。

代码：

#include <cstdio>
#include <cstring>
#include <vector>
using namespace std;
const int maxn=1005;
bool vis[maxn];
vector<int> graph[maxn];
int n,m,k;

void dfs(int v)
{
    vis[v]=true;
    for(auto u:graph[v])
        if(!vis[u]) dfs(u);
}

int func(int v)
{
    //cut
    memset(vis,false,sizeof(vis));
    vis[v]=true;
    //calculate the number of connected block
    int cnt=0;
    for(int i=1;i<=n;i++){
        if(!vis[i]){
            dfs(i);
            cnt++;
        }
    }
    return cnt-1;
}

int main()
{
    scanf("%d%d%d",&n,&m,&k);
    int u,v;
    for(int i=0;i<m;i++){
        scanf("%d%d",&u,&v);
        graph[u].push_back(v);
        graph[v].push_back(u);
    }
    int query;
    while(k--){
        scanf("%d",&query);
        printf("%d
",func(query));
    }
    return 0;
}