点割集

# include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;
const int N = 100;
int num[N], flag[N], low[N], root, V, E, index = 0, e[N][N];
void dfs(int cur, int father) {
    int child = 0;
    index++;
    num[cur] = index;
    low[cur] = index;
    for (int i = 1; i <= V; i++) {
        if (e[cur][i] == 1) {
            if (num[i] == 0) {
                child++;
                dfs(i, cur);
                low[cur] = min(low[cur], low[i]);
                if (cur == root&&child == 2)
                    flag[cur] = 1;
                if (cur != root&&low[i] >= num[cur])
                    flag[cur] = 1;
            }
            else if (i != father) {
                low[cur] = min(low[cur], num[i]);
            }
        }
    }
}