PAT--1094. The Largest Generation

题解

dfs

bfs

#include <iostream>
#include <algorithm>
#include <cstdio>
#include <vector>
#include <map>
#include <queue>
using namespace std;

const int maxn = 100;
vector<int> G[maxn];
map<int, int> mp;
int d[maxn];
int n, m;

void dfs(int u, int depth){
d[u] = depth;
mp[depth]++;
for(int i = 0; i < G[u].size(); ++i){
int v = G[u][i];
dfs(v, depth + 1);
}
}

void bfs(){
queue<int> Q;
Q.push(1);
int tail = 1, flag = 0;
int level = 1, largest = 1, ansLevel = 1;
int cnt = 0;
while(!Q.empty()){
int u = Q.front();
Q.pop();
cnt += G[u].size();
for(int i = 0; i < G[u].size(); ++i){
int v = G[u][i];
Q.push(v);
flag = v;
}
if(u == tail){
tail = flag;
level++;
if(cnt > largest){
largest = cnt;
ansLevel = level;
}
cnt = 0;
}
}
cout << largest << " " << ansLevel << endl;
}

int main(){
#ifndef ONLINE_JUDGE
freopen("data.in", "r", stdin);
#endif // ONLINE_JUDGE

cin >> n >> m;
int id, k, u;
for(int i = 0; i < m; ++i){
cin >> id >> k;
for(int j = 0; j < k; ++j){
cin >> u;
G[id].push_back(u);
}
}
dfs(1, 1);
int level = 0, largest = 0;
for(auto it = mp.begin(); it != mp.end(); ++it){
if(it->second > largest){
largest = it->second;
level = it->first;
}
}
cout << largest << " " << level << endl;
//    bfs();

return 0;
}