http://oj.acm.zstu.edu.cn/JudgeOnline/problem.php?id=4398

C++版本一

题解：背包问题

贪心解法


#include <stdio.h>
#include <stdlib.h>
#include <math.h>
/* run this program using the console pauser or add your own getch, system("pause") or input loop */
int main(int argc, char *argv[]) {
    int a;
    scanf("%d",&a);
    while(a--){
        int n,m;
        int t[101];
        scanf("%d %d",&n,&m);
        int i,j;
        for(i=0;i<n;i++){
            scanf("%d",&t[i]);
        }
        int temp,k;
        for(i=0;i<n;i++){
            k=i;
            for(j=i+1;j<n;j++)
                if(t[k]<t[j])
                    k=j;
            if(k!=i){
                temp=t[k];t[k]=t[i];t[i]=temp;
            }
        }
        int sum=0;
        for(i=0;i<m;i++){
            sum+=t[i];
        }
        printf("%d\n",sum);
    }
    return 0;
}

C++版本二

DP

/*
*@Author:   STZG
*@Language: C++
*/
#include <bits/stdc++.h>
#include<iostream>
#include<algorithm>
#include<cstdlib>
#include<cstring>
#include<cstdio>
#include<string>
#include<vector>
#include<bitset>
#include<queue>
#include<deque>
#include<stack>
#include<cmath>
#include<list>
#include<map>
#include<set>
//#define DEBUG
#define RI register int
using namespace std;
typedef long long ll;
//typedef __int128 lll;
const int N=10000;
const int MOD=1e9+7;
const double PI = acos(-1.0);
const double EXP = 1E-8;
const int INF = 0x3f3f3f3f;
int t,n,m,k,q;
int dp[N];
int main()
{
#ifdef DEBUG
	freopen("input.in", "r", stdin);
	//freopen("output.out", "w", stdout);
#endif
    scanf("%d",&t);
    while(t--){
        memset(dp,0,sizeof(dp));
        scanf("%d%d",&n,&m);
        for(int i=1;i<=n;i++){
            scanf("%d",&k);
            for(int j=m;j>=1;j--){
                dp[j]=max(dp[j],dp[j-1]+k);
            }
        }
        printf("%d\n",dp[m]);
    }
    //cout << "Hello world!" << endl;
    return 0;
}