題意

題面說的很清楚

#include<iostream>
#include<cstring>
#include<cstdio>
using namespace std;

int n,m,ans=0;
int fa[2010],res[2010];

int getfa(int x){return fa[x]==x?fa[x]:fa[x]=getfa(fa[x]);}
int main()
{
    int n,m;
    scanf("%d%d",&n,&m);
    memset(res,0,sizeof(res));
    for (int i=1;i<=2*n;i++) fa[i]=i;
    for (int i=0;i<m;i++)
    {
        char c;int x,y;
        scanf(" %c%d%d",&c,&x,&y);
        if (c=='F')
        {
            int p=getfa(x),q=getfa(y);
            fa[p]=q;
        }
        else
        {
            int p=getfa(x),pp=getfa(x+n),q=getfa(y),qq=getfa(y+n);
            fa[pp]=q;fa[p]=qq;
        }
    }
    for (int i=1;i<=n;i++) res[getfa(i)]++;
    for (int i=1;i<=2*n;i++) if (res[i]) ans++;
    printf("%d\n",ans);
    return 0;
}