hdu 2159 二维背包

重点是建立背包模型，确定哪个作为花费，哪个作为收益，

我是将杀怪数量和忍耐度作为容量，经验值作为收益进行背包操作，最后再扫描一遍找到最小的

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#define MAX 107

using namespace std;

int w[MAX];
int c[MAX];
int dp[MAX][MAX];

int main ( )
{
    int n,m,k,s;
    while ( ~scanf ( "%d%d%d%d" , &n , &m , &k , &s ) )
    {
        for ( int i = 1 ; i <= k ; i ++ )
            scanf ( "%d %d" , &w[i] , &c[i] );
        memset ( dp , 0, sizeof ( dp ) );
        for ( int i = 1 ; i <= k ; i++ )
            for ( int t = 1 ; t <= s ; t++ )
                for ( int j = c[i] ; j <= m ; j++ )
                    dp[j][t] = max ( dp[j][t] , dp[j-c[i]][t-1] + w[i] );
        int ans  = m+1;
        for ( int i = 1 ; i <= m ; i++ )
        {
            for ( int t = 1 ; t <= s ; t++ )
                if ( dp[i][t] >= n )
                {
                    ans = i;
                }
            if ( ans == i ) break;
        }
        printf ( "%d\n" , m-ans );
    }
}