Submission #44615

#	Time	Username	Problem	Language	Result	Execution time	Memory
44615		ulna	Paprike (COI18_paprike)	C++11	100 / 100	95 ms	16744 KiB

paprike

#include <bits/stdc++.h>
using namespace std;
 
// why am I so weak
 
int n, k;
int a[100055];
long long dp[100055];
 
vector<int> g[100055];
 
int dfs(int v, int par = -1) {
	dp[v] = a[v];
	int res = 0;
 
	for (auto u : g[v]) if (u != par) {
		res += dfs(u, v);
		dp[v] += dp[u];
	}
 
	sort(g[v].begin(), g[v].end(), [&] (int u, int v) {
		return dp[u] > dp[v];
	});
 
	for (auto u : g[v]) if (u != par) {
		if (dp[v] <= k) break;
 
		res++;
		dp[v] -= dp[u];
	}
 
	return res;
}
int main() {
	cin >> n >> k;
 
	for (int i = 0; i < n; i++) scanf("%d", &a[i]);
 
	for (int i = 0; i + 1 < n; i++) {
		int x, y;
		scanf("%d %d", &x, &y);
		x--, y--;
 
		g[x].push_back(y);
		g[y].push_back(x);
	}
 
	printf("%d\n", dfs(0));
 
	return 0;
}

Compilation message (stderr)

paprike.cpp: In function 'int main()':
paprike.cpp:37:35: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for (int i = 0; i < n; i++) scanf("%d", &a[i]);
                              ~~~~~^~~~~~~~~~~~~
paprike.cpp:41:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d", &x, &y);
   ~~~~~^~~~~~~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 13 / 13
• Subtask 3: 27 / 27
• Subtask 4: 49 / 49