Submission #61851

#	Time	Username	Problem	Language	Result	Execution time	Memory
61851		IvanC	Chase (CEOI17_chase)	C++17	100 / 100	805 ms	358920 KiB

chase

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

typedef long long ll;

const int MAXN = 1e5 + 10;
const int MAXC = 1e2 + 5;

vector<int> grafo[MAXN];
ll dp[MAXN][MAXC][2],P[MAXN],somatorio[MAXN],best;
ll copia[MAXN][MAXC],copia_sigma[MAXN],atual[MAXN][MAXC];
int N,C;

void adicona(int v,int u){
	for(int i = 1;i<=C;i++){
		if(atual[u][i] > dp[v][i][0]){
			dp[v][i][1] = dp[v][i][0];
			dp[v][i][0] = atual[u][i];
		}
		else if(atual[u][i] > dp[v][i][1]){
			dp[v][i][1] = atual[u][i];
		}
	}
	somatorio[v] += P[u];
}

void tira(int v,int u){
	for(int i = 1;i<=C;i++){
		if(atual[u][i] == dp[v][i][0]){
			dp[v][i][0] = dp[v][i][1];
		}
	}
	somatorio[v] -= P[u];
}

void faz_copia(int v){
	for(int i = 0;i<=C;i++){
		copia[v][i] = dp[v][i][0];
	}
	copia_sigma[v] = somatorio[v];
}

void restaura(int v){
	for(int i = 0;i<=C;i++){
		dp[v][i][0] = copia[v][i];
	}
	somatorio[v] = copia_sigma[v];
}

void calcula(int v){
	for(int i = 1;i<=C;i++){
		atual[v][i] = max(dp[v][i][0], dp[v][i-1][0] + somatorio[v] );
	}
}

void dfs1(int v,int p){
	
	for(int u : grafo[v]){
		if(u == p) continue;
		dfs1(u,v);
		adicona(v,u);
	}

	calcula(v);

}

void dfs2(int v,int p){

	calcula(v);
	faz_copia(v);
	for(int i = 0;i<=C;i++){
		best = max(best,atual[v][i]);
	}


	for(int u : grafo[v]){
		if(u == p) continue;
		tira(v,u);
		calcula(v);
		adicona(u,v);
		dfs2(u,v);
		restaura(v);
	}

}

int main(){

	scanf("%d %d",&N,&C);
	for(int i = 1;i<=N;i++){
		scanf("%lld",&P[i]);
	}
	for(int i = 1;i<N;i++){
		int u,v;
		scanf("%d %d",&u,&v);
		grafo[u].push_back(v);
		grafo[v].push_back(u);
	}

	dfs1(1,-1);
	dfs2(1,-1);

	printf("%lld\n",best);

	return 0;
}

Compilation message (stderr)

chase.cpp: In function 'int main()':
chase.cpp:90:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d",&N,&C);
  ~~~~~^~~~~~~~~~~~~~~
chase.cpp:92:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%lld",&P[i]);
   ~~~~~^~~~~~~~~~~~~~
chase.cpp:96:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d",&u,&v);
   ~~~~~^~~~~~~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 20 / 20
• Subtask 3: 30 / 30
• Subtask 4: 30 / 30