无向图连通分量 | 1013 Battle Over Citie

用DFS做的。
一发ac，然而在本地调了蛮久。
刚开始直接删边（完全忘记了后面的k个是互相独立的，都是仅删去1个节点和连边233333），在dfs和is_conn()做点小改变就好啦2333333
1013 Battle Over Cities

#include <cstdio>
#include <vector>
#include <cstring>
using namespace std;
const int N = 1010;
int n, m, kk;
bool visited[N];
vector<int> graph[N];

void dfs(int curr, int del) {
    visited[curr] = true;
    for (int i = 0; i < graph[curr].size(); ++i) {
        int neighbor = graph[curr][i];
        if (!visited[neighbor] && neighbor != del)
            dfs(neighbor,del);
    }
}

int isConnected(int del) {
    for (int i = 1; i <= n; ++i) {
        if (i == del) continue;
        else if (visited[i]) continue;
        else return i;
    }
    return N;
}

int main() {
    scanf("%d%d%d", &n, &m, &kk);
    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 delc;
    vector<int>::iterator it;
    for (int j = 0; j < kk; ++j) {
        scanf("%d", &delc);
        memset(visited, false, sizeof(visited));
        if (n == 1) {
            puts("0");
            continue;
        }
        if (delc == 1) {
            dfs(2,delc);
        } else dfs(1,delc);
        for (int k = 0; k <= n; k++) {
            int not_conn = isConnected(delc);
            if (not_conn > n) {
                printf("%d\n", k);
                break;
            } else {
                dfs(not_conn,delc);
            }

        }
    }
    return 0;
}

另外提一下，map、vector删除（改变size）用erase(iterator++)
vector remove() vs erase()