Submission #41119

#	Time	Username	Problem	Language	Result	Execution time	Memory
41119		wzy	Biochips (IZhO12_biochips)	C++14	0 / 100	2048 ms	417708 KiB

biochips

#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <vector>
#include <algorithm>
#include <iostream>
#include <utility>
using namespace std;
#define eps (int) 1e9
#define pb push_back
int  root , rv[200005],  t = 0 , dp[200005][505] , c[200005] , n , m , st[200005] , ed[200005];
vector<int> adj[200005];

void dfs(int x , int y){
	st[x] = ++t;
	rv[st[x]] = x;
	for(int i = 0 ; i < adj[x].size() ; i++){
		int v = adj[x][i];
		if(v == y) continue;
		dfs(v,x);
	}
	ed[x] = t;
	return;
}

int solve(int i, int j){
	if(dp[i][j] != -1) return dp[i][j];
	if(j > m) return -eps;
	if(j == m) return 0;
	if(i > t) return  - eps;
	dp[i][j] = 0;
	return dp[i][j] = max(solve(i + 1 , j) , solve(ed[rv[i]] + 1 , j + 1) + c[rv[i]]);
}

int32_t main(){
	scanf("%d%d" , &n , &m);
	for(int i = 0 ; i < 200005 ; i++){
		c[i] = -eps;
		rv[i] = eps;
		ed[i] = eps;
		for(int j = 0 ; j < 505 ; j++) dp[i][j] = -1;
	}
	for(int i = 0 ; i <n; i++){
		int x , y;
		scanf("%d%d" , &x, &y);
		c[i] = y;
		if(x == 0){
			root = i;
			continue;
		}
		else{
			adj[i].pb(x-1);
			adj[x-1].pb(i);
		}
	}
	dfs(root, root);
	int qq = solve(st[root] , 0);
	printf("%d\n" , qq);
}

Compilation message (stderr)

biochips.cpp: In function 'void dfs(int, int)':
biochips.cpp:17:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0 ; i < adj[x].size() ; i++){
                    ^
biochips.cpp: In function 'int32_t main()':
biochips.cpp:36:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d" , &n , &m);
                         ^
biochips.cpp:45:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d" , &x, &y);
                         ^

• Subtask 1: 0 / 100