Submission #30848

#	Time	Username	Problem	Language	Result	Execution time	Memory
30848		Kerim	Biochips (IZhO12_biochips)	C++14	100 / 100	389 ms	12452 KiB

biochips

#include "bits/stdc++.h"
#define MAXN 200009
#define INF 1000000007
#define mp(x,y) make_pair(x,y)
#define all(v) v.begin(),v.end()
#define pb(x) push_back(x)
#define wr cout<<"----------------"<<endl;
#define ppb() pop_back()
#define tr(ii,c) for(__typeof((c).begin()) ii=(c).begin();ii!=(c).end();ii++)
#define ff first
#define ss second
#define my_little_dodge 46
#define debug(x)  cerr<< #x <<" = "<< x<<endl;
using namespace std;

typedef long long ll;
typedef pair<int,int> PII;
template<class T>bool umin(T& a,T b){if(a>b){a=b;return 1;}return 0;}
template<class T>bool umax(T& a,T b){if(a<b){a=b;return 1;}return 0;}
int arr[MAXN],go[MAXN],cost[MAXN],dp[2][MAXN],TIM,id[MAXN];
vector<int>adj[MAXN];
void dfs(int nd){
	int tm=++TIM;
	id[tm]=nd;
	tr(it,adj[nd])
		dfs(*it);
	go[tm]=TIM;
}
int main(){
	//~ #ifndef ONLINE_JUDGE
    //~ freopen("file.in", "r", stdin);
	//~ #endif	
	int n,m,root;
	scanf("%d%d",&n,&m);
	for(int i=1;i<=n;i++){
		int p;
		scanf("%d%d",&p,&arr[i]);
		if(p)
			adj[p].pb(i);
		else
			root=i;
	}dfs(root);
	for(int i=1;i<=n;i++)
		dp[1][i]=arr[id[i]];
	for(int i=2;i<=m;i++){cost[n+1]=-INF;
		for(int j=n;j>=1;j--)
			cost[j]=max(cost[j+1],dp[(i-1)&1][j]);
		for(int j=n;j>=1;j--)
			dp[i&1][j]=cost[go[j]+1]+arr[id[j]];
	}	
	int ans=0;
	for(int i=1;i<=n;i++)
		umax(ans,dp[m&1][i]);
	printf("%d\n",ans)	;	
	return 0;
}

Compilation message (stderr)

biochips.cpp: In function 'int main()':
biochips.cpp:34:21: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&n,&m);
                     ^
biochips.cpp:37:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d",&p,&arr[i]);
                           ^
biochips.cpp:42:12: warning: 'root' may be used uninitialized in this function [-Wmaybe-uninitialized]
  }dfs(root);
            ^

• Subtask 1: 100 / 100