Submission #10940

#	Time	Username	Problem	Language	Result	Execution time	Memory
10940		dohyun0324	우호 조약 체결 (JOI14_friends)	C++98	35 / 100	48 ms	10608 KiB

friends

#include<stdio.h>
#include<vector>
using namespace std;
vector<int>con[200010];
int f,r,n,m,x[100010],y[100010],group[100010],ranking[100010],cnt[100010],arr[100010],w,ch[100010];
long long dap;
int finding(int x)
{
    if(x==group[x]) return x;
    return finding(group[x]);
}
void union_find(int x,int y)
{
    int p,q;
    p=finding(x); q=finding(y);
    if(ranking[p]==ranking[q]){
        group[q]=p;
        ranking[p]++;
    }
    else if(ranking[p]>ranking[q]) group[q]=p;
    else group[p]=q;
}
int main()
{
    int i,j,k;
    scanf("%d %d",&n,&m);
    for(i=1;i<=n;i++) group[i]=i;
    for(i=1;i<=m;i++){
        scanf("%d %d",&x[i],&y[i]);
        con[x[i]].push_back(y[i]);
    }
    for(i=1;i<=n;i++){
        k=con[i].size();
        for(j=0;j<k-1;j++){
            union_find(con[i][j],con[i][j+1]);
            ch[con[i][j]]=1;
        }
        if(j>0) ch[con[i][j]]=1;
    }
    for(i=1;i<=n;i++){
        if(ch[i]) arr[++r]=i;
    }
    while(f!=r){
        f++;
        if(con[arr[f]].size()==0) continue;
        k=con[arr[f]][0];
        union_find(arr[f],k);
        if(ch[k]==0) ch[k]=1, arr[++r]=k;
    }
    for(i=1;i<=n;i++){
        group[i]=finding(i);
        cnt[group[i]]++;
    }
    for(i=1;i<=n;i++) dap+=(long long)cnt[i]*(long long)(cnt[i]-1);
    for(i=1;i<=m;i++){
        if(group[x[i]]!=group[y[i]]) dap++;
    }
    printf("%lld",dap);
    return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 30 / 30
• Subtask 3: 0 / 65