boj1058.cpp

#include <bits/stdc++.h>
#define INF 0x3f3f3f3f
using namespace std;
using pii = pair<int, int>;
int n, ans;
int friendGraph[51][51];
int dist[51][51];
int main() {
    cin >> n;

    for (int i = 0; i < n; i++)
        for (int j = 0; j < n; j++)
            dist[i][j] = INF;

    for (int i = 0; i < n; i++) {
        string s;
        cin >> s;
        for (int j = 0; j < s.size(); j++) {
            if (s[j] == 'Y') friendGraph[i][j] = 1, dist[i][j] = 1;
            else friendGraph[i][j] = 0;
        }
    }

    for (int k = 0; k < n; k++) {
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < n; j++) {
                if (dist[i][j] > dist[i][k] + dist[k][j]) {
                    dist[i][j] = dist[i][k] + dist[k][j];
                }
            }
        }
    }

    for (int i = 0; i < n; i++) {
        int cnt = 0;
        for (int j = 0; j < n; j++) {
            if (i == j) continue;
            if (dist[i][j] <= 2) cnt++;
        }
        ans = max(ans, cnt);
    }

    cout << ans << '\n';

}