HDU 2159 FATE 二维费用背包

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
using namespace std;
int  n,m,k,s,maxx;
const int K=1000+50;
const int inf=1e9+7;
int val[K],wei[K],dp[K][K];
void init(){
memset(dp,0,sizeof(dp));
maxx=inf;
return ;
}
int main(){
while(scanf("%d%d%d%d",&n,&m,&k,&s)!=EOF){
init();
for(int i=1;i<=k;i++) scanf("%d%d",&val[i],&wei[i]);
for(int i=1;i<=k;i++){
for(int j=1;j<=s;j++){
for(int p=wei[i];p<=m;p++){
dp[j][p]=max(dp[j][p],dp[j-1][p-wei[i]]+val[i]);
if(dp[j][p]>=n){
maxx=min(maxx,p);
}
}
}

}
if(maxx!=inf) printf("%d\n",m-maxx);
else printf("-1\n");
}
return 0;
}