2660 회장뽑기

#include <stdio.h>
#include <vector>
 
using namespace std;
 
#define INF 100000000;
int d[1000][1000] = { 0 };
int minNum=INF;
vector<int> rst;
 
int main() {
    int n;
    scanf("%d",&n);
        
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= n; j++) {
            d[i][j] = (i == j) ? 0 : INF;
        }
    }
 
    while (1) {
        int a, b;
        scanf("%d %d", &a, &b);
 
        if (a != -1 && b != -1) {
            d[a][b] = 1;
            d[b][a] = 1;
        }
            
        else
            break;
    }
 
    for (int k = 1; k <= n; k++) 
        for (int i = 1; i <= n; i++) 
            for (int j = 1; j <= n; j++) {
                if (d[i][j] > d[i][k] + d[k][j])
                    d[i][j] = d[i][k] + d[k][j];
            }
 
    for (int i = 1; i <= n; i++) {
        int tmp = 0;
        for (int j = 1; j <= n; j++) {
            tmp += d[i][j];
        }
        if (minNum > tmp)
            minNum = tmp;
    }
 
    int rstLargest = 0;
    for (int i = 1; i <= n; i++) {
        int tmp = 0, largest = 0;        
        for (int j = 1; j <= n; j++) {
            tmp += d[i][j];
            if (largest < d[i][j])
                largest = d[i][j];
        }
        if (tmp == minNum) {
            rst.push_back(i);
            rstLargest = largest;
        }
            
    }
 
    printf("%d %d\n", rstLargest, rst.size());
    for (int i = 0; i < rst.size(); i++)
        printf("%d ", rst[i]);
}