学步园

把东西分为两部分尽量相等，不相等则差值最小，

#include<stdio.h>
#include<string.h>
int f[250005];
int max(int a,int b)
{
    if(a>b)return a;
     return b;
}
int main()
{
    
    int w[5050],n,i,j,v,a,k,sum,half;
    
    while(scanf("%d",&n),n>0)
    {
        memset(f,0,sizeof(f));
        sum=k=0;
        for(i=0;i<n;i++)
        {
            scanf("%d%d",&v,&a);
            for(j=1;j<=a;j++)
            {
                w[k++]=v;sum=sum+v;
            }
        }
        n=k;half=sum/2;
        for(i=0;i<n;i++)
            for(j=half;j>=w[i];j--)
                f[j]=max(f[j-w[i]]+w[i],f[j]);
            printf("%d %d\n",max(f[half],sum-f[half]),sum-max(f[half],sum-f[half]));
    }
    return 0;
}