HDOJ(HDU).4508 湫湫系列故事――减肥记I (DP 完全背包)

HDOJ(HDU).4508 湫湫系列故事――减肥记I (DP 完全背包)

题意分析

裸完全背包

代码总览

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#define nmax 100005
#define nn 105
using namespace std;
int dp[nmax];
struct item{
    int hap;
    int kal;
    double rate;
}a[nmax];
bool cmp(item a,item b)
{
    return a.rate>b.rate;
}
int main()
{
    //freopen("in.txt","r",stdin);
    int n;
    while(scanf("%d",&n) != EOF){
        memset(dp,0,sizeof(dp));
        for(int i = 1; i<=n; ++i) {scanf("%d%d",&a[i].hap,&a[i].kal); a[i].rate = a[i].hap/a[i].kal;}
        sort(a+1,a+1+n,cmp);
        int m;
        scanf("%d",&m);
        for(int i =1; i<=n; ++i){
            for(int j =a[i].kal;j<=m;++j){
                dp[j] = max(dp[j],dp[j-a[i].kal]+a[i].hap);
            }
        }
        printf("%d\n",dp[m]);

    }
    return 0;
}