11724번: 연결 요소의 개수

#include<cstdio>
#include<algorithm>
using namespace std;
void dfs(bool(*pnt)[1001], int x, int n);
int main()
{
    bool pnt[1001][1001];
    for (int i = 0; i < 1001; ++i)
        for (int j = 0; j < 1001; ++j)
            pnt[i][j] = 0;
    int n, m, ans = 0;
    scanf("%d %d", &n, &m);
    for (int i = 0, u, v; i < m; ++i)
    {
        scanf("%d %d", &u, &v);
        pnt[u-1][v-1] = 1;
        pnt[v-1][u-1] = 1;
    }
    for (int i = 0; i < n; ++i)
        for (int j = 0; j < n; ++j)
            if (pnt[i][j] == 1)
            {
                dfs(pnt, i, n);
                ++ans;
            }
    for (int i = 0; i < n; ++i)
        ans = (pnt[1000][i] == false) ? ans + 1 : ans;
    printf("%d", ans);
}
void dfs(bool(*pnt)[1001], int x, int n)
{
    pnt[1000][x] = 1;
    for (int i = 0; i < n; ++i)
        pnt[i][x] = 0;
    for (int i = 0; i < n; ++i)
        if (pnt[x][i])
            dfs(pnt, i, n);
}