10ptsWA求助

/*

*/
#include<bits/stdc++.h>
#define itn int
#define el "\n"
#define db double
#define ll long long
#define for0(n,i) for(int i=0;i<n;i++)
#define for1(n,i) for(int i=1;i<=n;i++)
using namespace std;
ll dp[1000][1000];//dp[i][j]:i个车j个人时的最小花费
int main(){
//	freopen(".in","r",stdin);
//	freopen(".out","w",stdout);
	int n,k,s,d;
	cin>>n>>k>>d>>s;
	ll t[k+1],z[k+1];
	for1(k,i){
		cin>>t[i]>>z[i];
	}
	for1(n,i){
		dp[0][i]=INT_MAX;
	}
	for1(k,i){
		for1(n,j){
			dp[i][j]=min(dp[i-1][j],dp[i-1][max(j-z[i],(ll)0)]+10+min(z[i],(ll)j)*t[i]);
		}
	}
//	for1(k,i){
//		for1(n,j){
//			cout<<dp[i][j]<<"\t";
//		}
//		cout<<el;
//	}
	dp[k][n]<1000000000?cout<<dp[k][n]:cout<<"impossible";
	system("pause");
	return 0;
}

/*




*/