題目鏈接：https://vjudge.net/contest/103424#problem/K

題目大意：

給n個物品，和m塊錢，輸出能夠購買最多物品的個數和購買這麽多物品的方案數。

#include <cstring>
#include <iostream>
#include <algorithm>
#define clr(a) (memset(a,0,sizeof(a)))
using namespace std;
int dp[510][50], a[50];
int n, m;
int main()
{
    int T;
    scanf("%d", &T);
    
 
while (T--)
    {
        scanf("%d %d", &n, &m);
        for (int i = 1; i <= n; i++)scanf("%d", &a[i]);
        clr(dp);
        dp[0][0] = 1;
        int mx = 0;
        for (int i = 1; i <= n; i++)
            for (int j = m; j >= a[i]; j--)
            {
                for (int
 
 k = n - 1; k >= 0; k--)
                {
                    if (dp[j - a[i]][k])dp[j][k + 1] += dp[j - a[i]][k];      
                    mx = max(mx, k + 1);             //mx為最多能買幾件物品
                }
            }
        if (mx == 0)
        {
            puts("Sorry, you can‘t buy anything."
 
);
            continue;
        }
        int ans = 0;           //ans為能夠買mx件物品的選擇方案總數（mx為最多能購買的物品數量）
        for (int i = 0; i <= m; i++)ans += dp[i][mx];
        printf("You have %d selection(s) to buy with %d kind(s) of souvenirs.\n", ans, mx);
    }
    return 0;
}

2018-05-21

hdu 2126 Buy the souvenirs 【輸出方案數】【01背包】（經典）