PTA 1013 Battle Over Cities

#include <iostream>
#include <stdio.h>
#include <string.h>

using namespace std;

int graph[1010][1010]={0};
int visited[1010] = {0};
int check[1010] = {0};
int N,M,K;

void DFS(int i)
{
    visited[i] = 1;
    for(int j = 1;j<=N;j++)
    {
        if((visited[j] == 0)&&(graph[i][j] == 1))
            DFS(j);
    }
}


int main()
{

    scanf("%d %d %d",&N,&M,&K);

    for(int i=1;i<=M;i++)
    {
        int h,j;
        scanf("%d %d",&h,&j);
        graph[h][j] = 1;
        graph[j][h] = 1;
    }
    for(int i=1;i<=K;i++)
    {
        int tmp;
        scanf("%d",&tmp);
        check[i] = tmp;
    }

    for(int i=1;i<=K;i++)
    {
        int sum_cc = 0;
        memset(visited,0,sizeof(visited));
        int ck = check[i];
        visited[ck] = 1;
        for(int j = 1;j<=N;j++)
        {
            if(visited[j]==0){
                DFS(j);
                sum_cc++;
            }
        }
        cout<<sum_cc-1<<endl;
    }
    return 0;
}