POJ 2184

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <climits>
#include <string.h>
using namespace std;
int dp[200010];
struct Cow{
	int s,f;
}cow[105];


int main(){
	int n,positive,negative,sum;
	while(scanf("%d",&n)!=EOF){
		positive=negative=0;
		for(int i=1;i<=n;i++){
			scanf("%d%d",&cow[i].s,&cow[i].f);
			if(cow[i].s<0)
			negative+=(-cow[i].s);
			else{
				positive+=(cow[i].s);
			}
		}
		for(int i=0;i<200010;i++)
		dp[i]=INT_MIN;
		int sum=negative+positive;
		dp[negative]=0;
		for(int i=1;i<=n;i++){
			if(cow[i].s<0){
				for(int p=-negative;p<=positive;p++){
					if(dp[p-cow[i].s+negative]!=INT_MIN&&p-cow[i].s+negative>=0){
						dp[p+negative]=max(dp[p+negative],dp[p-cow[i].s+negative]+cow[i].f);
					}
				}
			}
			else{
				for(int p=positive	 ;p>=-negative	;p--){
					if(dp[p-cow[i].s+negative]!=INT_MIN&&p-cow[i].s+negative>=0){
						dp[p+negative]=max(dp[p+negative],dp[p-cow[i].s+negative]+cow[i].f);
					}
				}
			}
		}
		int ans=INT_MIN;
		for(int i=0	;i<=positive	;i++){
			if(dp[i+negative]>=0){
				ans=max(ans,i+dp[i+negative]);
			}
		}
		printf("%d\n",ans);
	}
	return 0;
}