Submission #127154

#	Time	Username	Problem	Language	Result	Execution time	Memory
127154		wilwxk	Designated Cities (JOI19_designated_cities)	C++14	39 / 100	2053 ms	56568 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];
bool marc[MAXN];
ll dp[MAXN];
ll respf[MAXN], somaf;
int n, q, raiz;

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 recalc(int cur, int p) {
	dp[cur]=0;
	mprof[cur][0]=mprof[cur][1]={0, cur};
	for(auto aresta : g[cur]) {
		int viz; ll peso, rpeso;
		tie(viz, peso, rpeso)=aresta;
		if(viz==p) continue;
		recalc(viz, cur);

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

void dfs(int cur, int p) {
	respf[1]=max(respf[1], dp[cur]);
	if(dp[cur]+mprof[cur][0].first>respf[2]) {
		respf[2]=dp[cur]+mprof[cur][0].first;
		raiz=cur;
	}
	// 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==mprof[viz][0].second) mprof[cur][0]=mprof[cur][1];
		melhora(viz, {mprof[cur][0].first+rpeso, mprof[cur][0].second});

		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;
	}
}

void pinta(int cur, int p, int alvo) {
	if(cur==alvo) marc[cur]=1;
	for(auto aresta : g[cur]) {
		int viz; ll peso, rpeso;
		tie(viz, peso, rpeso)=aresta;
		if(viz==p) continue;
		pinta(viz, cur, alvo);
		if(marc[viz]) marc[cur]=1;
	}
}

ll responde(int val) {
	if(respf[val]!=0) return respf[val];
	respf[val]=responde(val-1);
	respf[val]+=mprof[raiz][0].first;
	int cara=mprof[raiz][0].second;
	pinta(raiz, raiz, cara);
	recalc(raiz, raiz);
	return respf[val];
}

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;
	}

	recalc(1, 1);
	dfs(1, 1);
	recalc(raiz, raiz);
	pinta(raiz, raiz, mprof[raiz][0].second);
	recalc(raiz, raiz);

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

Compilation message (stderr)

designated_cities.cpp: In function 'int main()':
designated_cities.cpp:89:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
  ~~~~~^~~~~~~~~~
designated_cities.cpp:91:24: 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:102:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &q);
  ~~~~~^~~~~~~~~~
designated_cities.cpp:104:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   int val; scanf("%d", &val);
            ~~~~~^~~~~~~~~~~~

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