1014. Waiting in Line (30)

深度优先遍历求连通分量的个数。代码如下：

#include<cstdio>#include<cstring>using namespace std;#define N 1001 int map[N][N]; int n; void dfs(int * mark,int map[N][N],int node){    int i;    mark[node]=1;    for(i=1;i<=n;i++){        if(map[node][i]&&mark[i]==0)         dfs(mark,map,i);    }} int getN(int k){    int i;    int counter=0;    int mark[N];    memset(mark,0,sizeof(mark));    mark[k] = 1;    for(i=1;i<=n;i++){        if(mark[i]==0){            dfs(mark,map,i);            counter++;        }    }    return counter; }int main(){    int m,k;    int i,j;    int c1,c2;    memset(map,0,sizeof(map));    scanf("%d %d %d",&n,&m,&k);    for(i=0;i<m;i++){        scanf("%d %d",&c1,&c2);        map[c1][c2] = map[c2][c1] =1;    }    for(i=0;i<k;i++){        scanf("%d",&c1);        printf("%d\n",getN(c1)-1);    }}