Submission #127165

#	Time	Username	Problem	Language	Result	Execution time	Memory
127165		wilwxk	Designated Cities (JOI19_designated_cities)	C++14	100 / 100	815 ms	78360 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];
pair<ll, int> seg[MAXN*4];
ll lz[MAXN*4];
ll dp[MAXN], respf[MAXN], ppai[MAXN], somaf;
int tini[MAXN], tfim[MAXN], tcara[MAXN], pai[MAXN];
bool marc[MAXN];
int n, q, raiz, contt;

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) {	
	mprof[cur][0]={0, cur};
	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, mprof[viz][0].second});
	}
	tfim[cur]=contt;
}

void gira(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});

		gira(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 refresh(int sind, int ini, int fim) {
	seg[sind].first+=lz[sind];
	if(ini==fim) {
		lz[sind]=0;
		seg[sind].second=tcara[ini];
		return;
	}
	int e=sind*2; int d=e+1;
	lz[e]+=lz[sind];
	lz[d]+=lz[sind];
	lz[sind]=0;
}
void update(int sind, int ini, int fim, int qini, int qfim, ll val) {
	refresh(sind, ini, fim);
	if(qini>fim||qfim<ini) return;
	if(qini<=ini&&qfim>=fim) {
		lz[sind]+=val;
		refresh(sind, ini, fim);
		return;
	}
	int m=(ini+fim)/2; int e=sind*2; int d=e+1;
	update(e, ini, m, qini, qfim, val);
	update(d, m+1, fim, qini, qfim, val);
	seg[sind]=max(seg[e], seg[d]);
}

void dfs(int cur, int p, ll d) {
	tini[cur]=++contt;
	for(auto aresta : g[cur]) {
		int viz; ll peso, rpeso;
		tie(viz, peso, rpeso)=aresta;
		if(viz==p) continue;
		dfs(viz, cur, d+peso);
		pai[viz]=cur;
		ppai[viz]=peso;
	}
	tfim[cur]=contt;
	tcara[tini[cur]]=cur;
	update(1, 1, n, tini[cur], tini[cur], d);
	// printf("update %d +%lld\n", tini[cur], d);
} 

void pinta(int cur) {
	while(!marc[cur]) {
		marc[cur]=1;
		update(1, 1, n, tini[cur], tfim[cur], -ppai[cur]);
		cur=pai[cur];
	}
}

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);
	gira(1, 1);
	dfs(raiz, raiz, 0);
	marc[raiz]=1;
	pinta(seg[1].second);

	// for(int i=1; i<=n; i++) printf("%d >> %d %d >> %lld %d\n", i, tini[i], tfim[i], ppai[i], pai[i]);

	for(int i=3; i<=n; i++) {
		respf[i]=respf[i-1]+seg[1].first;
		int cara=seg[1].second;
		pinta(cara);
		// printf("%d usa %d\n", i, cara);
	}

	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:119:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
  ~~~~~^~~~~~~~~~
designated_cities.cpp:121:24: 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:141:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &q);
  ~~~~~^~~~~~~~~~
designated_cities.cpp:143:17: 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: 17 / 17
• Subtask 6: 44 / 44