Submission #666746

#	Time	Username	Problem	Language	Result	Execution time	Memory
666746		Kalashnikov	Hard route (IZhO17_road)	C++17	0 / 100	7 ms	12072 KiB

road

#include <bits/stdc++.h>
 
#define ios ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define file(s) if (fopen(s".in", "r")) freopen(s".in", "r", stdin), freopen(s".out", "w", stdout)
#define all(a) a.begin() , a.end()
#define F first
#define S second
 
using namespace std;
using ll = long long;
 
const int N = 5e5+5 , inf = 2e9 + 7;
const ll INF = 1e18 ,   mod = 1e9+7 , P = 6547;

int a[N];
vector<int> g[N];

pair<int,int> diam(int v, int dep = 0, int p = 0) {
	pair<int,int> res = {dep , v};
	for(auto to: g[v]) {
		if(to != p) {
			res = max(res, diam(to , dep+1 , v));
		}
	}
	return res;
}

void getw(int v,  int fn, vector<int> &dw , int p = 0) {
	if(v == fn) {
		dw.push_back(v);
		return;
	}
	for(auto to: g[v]) {
		if(to != p) {
			getw(to, fn, dw , v);
			if(dw.size()) {
				dw.push_back(v);
				return;
			}
		}
	}
}

void solve(int tc) {
	int n;
	cin >> n;
	for(int i = 1; i < n; i ++) {
		int a , b;
		cin >> a >> b;
		g[a].push_back(b);
		g[b].push_back(a);
	}
	int ans = 0 , cans = 1;
	for(int i = 1; i <= n; i ++) {
		vector<int> vec;
		for(auto to: g[i]) {
			vec.push_back(diam(to,0,i).F+1);
		}
		sort(all(vec));
		for(int j = 0; j < vec.size(); j ++) {
			for(int k = 0; k < vec.size(); k ++) {
				if(j == k) continue;
				for(int t = k+1; t < vec.size(); t ++) {
					if(t == j || t == k) continue;
					int res = vec[j]*(vec[k]+vec[t]);
					if(res == ans) cans ++;
					if(res > ans) {
						ans = res;
						cans = 1;
					}
				}
			}
		}
	}
	cout << ans << ' ' << cans << '\n';
}
/*
*/
main() {
    ios;
    int tt = 1 , tc = 0;
    // cin >> tt;
    while(tt --) {
        solve(++tc);
    }
    return 0;
}

Compilation message (stderr)

road.cpp: In function 'void solve(int)':
road.cpp:60:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   60 |   for(int j = 0; j < vec.size(); j ++) {
      |                  ~~^~~~~~~~~~~~
road.cpp:61:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   61 |    for(int k = 0; k < vec.size(); k ++) {
      |                   ~~^~~~~~~~~~~~
road.cpp:63:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   63 |     for(int t = k+1; t < vec.size(); t ++) {
      |                      ~~^~~~~~~~~~~~
road.cpp: At global scope:
road.cpp:79:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   79 | main() {
      | ^~~~

• Subtask 1: 0 / 19
• Subtask 2: 0 / 33
• Subtask 3: 0 / 48