Submission #127119

#	Time	Username	Problem	Language	Result	Execution time	Memory
127119		wilwxk	Designated Cities (JOI19_designated_cities)	C++14	7 / 100	423 ms	39496 KiB

designated_cities

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

const int MAXN=2e5+5;
vector<tuple<int, ll, ll> > g[MAXN];
ll dp[MAXN];
ll respf[MAXN], somaf;
int n, q;

void predfs(int cur, int p) {
	for(auto aresta : g[cur]) {
		int viz; ll peso, rpeso;
		tie(viz, peso, rpeso)=aresta;
		if(viz==p) continue;
		predfs(viz, cur);
		dp[cur]+=dp[viz]+rpeso;
	}
}

void dfs(int cur, int p) {
	respf[1]=max(respf[1], dp[cur]);
	// printf("dp[%d]= %lld\n", cur, dp[cur]);
	for(auto aresta : g[cur]) {
		int viz; ll peso, rpeso;
		tie(viz, peso, rpeso)=aresta;
		if(viz==p) continue;

		ll dpc=dp[cur], dpv=dp[viz];
		dp[cur]-=(dp[viz]+rpeso);
		dp[viz]+=(dp[cur]+peso);

		dfs(viz, cur);

		dp[cur]=dpc;
		dp[viz]=dpv;
	}
}

int main() {
	scanf("%d", &n);
	for(int i=1; i<n; i++) {
		int a, b, c, d; scanf("%d %d %d %d", &a, &b, &c, &d);
		g[a].push_back({b, c, d}); g[b].push_back({a, d, c});
		somaf+=c; somaf+=d;
	}

	predfs(1, 1);
	dfs(1, 1);

	scanf("%d", &q);
	while(q--) {
		int val; scanf("%d", &val);
		printf("%lld\n", somaf-respf[val]);
	}
}

Compilation message (stderr)

designated_cities.cpp: In function 'int main()':
designated_cities.cpp:41:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
  ~~~~~^~~~~~~~~~
designated_cities.cpp:43:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   int a, b, c, d; scanf("%d %d %d %d", &a, &b, &c, &d);
                   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
designated_cities.cpp:51:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &q);
  ~~~~~^~~~~~~~~~
designated_cities.cpp:53:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   int val; scanf("%d", &val);
            ~~~~~^~~~~~~~~~~~

• Subtask 1: 0 / 6
• Subtask 2: 7 / 7
• Subtask 3: 0 / 9
• Subtask 4: 0 / 17
• Subtask 5: 0 / 17
• Subtask 6: 0 / 44