Submission #660914

#	Time	Username	Problem	Language	Result	Execution time	Memory
660914		Trisanu_Das	Mag (COCI16_mag)	C++17	0 / 120	1178 ms	262144 KiB

mag

#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e6 + 10;
vector<int> adj[maxn], len[maxn];
int a[maxn], dp[maxn];
int n;
 
void add(int x, int t) {
	if (len[x][0] <= t) swap(len[x][0], t);
	len[x][1] = max(len[x][1], t);
}
 
int get(int x, int t=0) {return (a[x] == 1) * (len[x][t] + 1);}
 
int dfs(int x, int p = 0) {
	len[x] = {0, 0};
	for (int v : adj[x]) {
		if (v == p) continue;
		add(x, dfs(v, x));
	}
	return get(x);
}
 
int dfs_root(int x, int p = 0) {
	if (p) {
		int l = (a[p] == 1) *  get(p, len[p][0] == get(x));
		add(x, l);
	}
	dp[x] = len[x][0] + len[x][1];
	for (int v : adj[x]) {
		if (v == p) continue;
		dfs_root(v, x);
	}
}
 
int main() {
	cin >> n;
	for (int i = 1; i < n; i++) {
		int a, b; cin >> a >> b;
		adj[a].emplace_back(b);
		adj[b].emplace_back(a);
	}
	for (int i = 1; i <= n; ++i) cin >> a[i];
	dfs(1);
	dfs_root(1);
	int x = -1, y = -1;
	for (int i = 1; i <= n; ++i) {
		if (x == -1 or x *1ll* (dp[i] + 1) > a[i] *1ll* y) {
			x = a[i];
			y = dp[i] + 1;
		}
	}
	int g = __gcd(x, y);
	cout << x/g << '/' << y/g << '\n';
	return 0;
}

Compilation message (stderr)

mag.cpp: In function 'int dfs_root(int, int)':
mag.cpp:34:1: warning: no return statement in function returning non-void [-Wreturn-type]
   34 | }
      | ^

• Subtask 1: 0 / 12
• Subtask 2: 0 / 12
• Subtask 3: 0 / 12
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