Submission #90270

#	Time	Username	Problem	Language	Result	Execution time	Memory
90270		antimirage	Biochips (IZhO12_biochips)	C++14	100 / 100	589 ms	409256 KiB

biochips

#include <bits/stdc++.h>

#define fr first
#define sc second
#define mk make_pair
#define pb emplace_back
#define all(s) s.begin(), s.end()

using namespace std;

const int N = 2e5 + 5;

int n, m, x, y, root, a[N];

int dp[N][505], tin[N], tiktak, inf = 1e9 + 7, tout[N], ans, last;

vector < vector <int> > g;

vector < pair <int, int> > vec;

void dfs (int v)
{
	tin[v] = ++tiktak;
		
	for (auto to : g[v])
		dfs(to);
		
	tout[v] = tiktak;
	
	vec.pb( mk( tout[v], v ) );
}

main() 
{
	cin >> n >> m;
	g.resize(n + 1);
	
	for (int i = 1; i <= n; i++){
		scanf("%d%d", &x, &a[i]);
		if (x == 0)
			root = i;
		else
			g[x].pb(i);
	}
	dfs(root);
	
	sort( all(vec) );
	
	for (int i = 0; i <= n; i++)
		for (int j = 0; j <= m; j++)
			dp[i][j] = -inf;
			
	dp[0][0] = 0;
	
	for (auto it : vec)
	{	
		for (int l = last + 1; l <= it.fr; l++)
			for (int j = 0; j <= m; j++)
				dp[l][j] = max( dp[l][j], dp[l - 1][j] );
				
		for (int j = 1; j <= m; j++)
			dp[it.fr][j] = max( dp[ tin[it.sc] - 1 ][j - 1] + a[it.sc], dp[it.fr][j] );
			
				
		last = it.fr;
	}
	for (int j = 1; j <= n; j++)
		ans = max(dp[j][m], ans);
		
	cout << ans << endl;
}

Compilation message (stderr)

biochips.cpp:33:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main() 
      ^
biochips.cpp: In function 'int main()':
biochips.cpp:39:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d", &x, &a[i]);
   ~~~~~^~~~~~~~~~~~~~~~~~~

• Subtask 1: 100 / 100