제출 #127137

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
127137		wilwxk	Designated Cities (JOI19_designated_cities)	C++14	16 / 100	500 ms	59152 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];
pair<ll, int> mprof[MAXN][2];
ll dp[MAXN];
ll respf[MAXN], somaf;
int n, q;

void melhora(int cur, pair<ll, int> val) {
	if(val.first>=mprof[cur][0].first) {
		mprof[cur][1]=mprof[cur][0];
		mprof[cur][0]=val;
	}
	else if(val.first>mprof[cur][1].first) {
		mprof[cur][1]=val;
	}
}

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;
		melhora(cur, {mprof[viz][0].first+peso, viz});
	}
}

void dfs(int cur, int p) {
	respf[1]=max(respf[1], dp[cur]);
	respf[2]=max(respf[2], dp[cur]+mprof[cur][0].first);
	// printf("dp[%d]= %lld // mprof[%d][0]= %lld, %d\n", cur, dp[cur], cur, mprof[cur][0].first, mprof[cur][0].second);
	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];
		auto mprofc0=mprof[cur][0], mprofc1=mprof[cur][1];
		auto mprofv0=mprof[viz][0], mprofv1=mprof[viz][1];

		dp[cur]-=(dp[viz]+rpeso);
		dp[viz]+=(dp[cur]+peso);
		if(mprof[cur][0].second==viz) mprof[cur][0]=mprof[cur][1];
		melhora(viz, {mprof[cur][0].first+rpeso, cur});

		dfs(viz, cur);

		dp[cur]=dpc; dp[viz]=dpv;
		mprof[cur][0]=mprofc0; mprof[cur][1]=mprofc1;
		mprof[viz][0]=mprofv0; mprof[viz][1]=mprofv1;
	}
}

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]);
	}
}

컴파일 시 표준 에러 (stderr) 메시지

designated_cities.cpp: In function 'int main()':
designated_cities.cpp:61:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
  ~~~~~^~~~~~~~~~
designated_cities.cpp:63:24: 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:71:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &q);
  ~~~~~^~~~~~~~~~
designated_cities.cpp:73:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   int val; scanf("%d", &val);
            ~~~~~^~~~~~~~~~~~

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• Subtask 6: 0 / 44