HDU 1171(揹包)

#include <stdio.h>
#include <string.h>
#include <algorithm>
#include <iostream>
using namespace std;
int dp[250005];
int val[5005];
int sum;
int main()
{
    int t, a, b, cnt;
    while(cin>>t && ( t > 0))
    {
        cnt = 0;
        sum = 0;
        for(int i = 0; i < t; i++)
        {
            cin>>a>>b;
            while(b--)
            {
                sum +=  a;
                val[cnt++] = a;
            }
        }
        memset(dp, 0, sizeof dp);
        for(int i = 0; i < cnt; i++)
            for(int j = sum / 2; j >= val[i]; j--)
                dp[j] = max(dp[j], dp[j - val[i]] + val[i]);
        int x = dp[sum / 2], y = sum - dp[sum / 2];
        int maxn = max(x, y);
        cout<<maxn<<' '<<sum - maxn<<endl;
    }
    return 0;
}