学步园

简单完全背包。

代码如下：

#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <cstring>
#include <iostream>
#include <algorithm>
#define MAXN 500
#define INF 0x3ffffff
using namespace std;

int E, F, N, W, dp[10005];

struct Node
{
    int p, w;    
}e[MAXN+5];

void c_bag(int x)
{
    for (int i = e[x].w; i <= W; ++i) {
        if (dp[i-e[x].w] != INF) {
            dp[i] = min(dp[i], dp[i-e[x].w]+e[x].p);
        //    printf("i=%d, dp=%d\n", i, dp[i]);
        }
    }
}

void DP()
{
    for (int i = 1; i <= N; ++i) {
        c_bag(i);
    }  
}

int main()
{
    int T;
    scanf("%d", &T);
    while (T--) {
        scanf("%d %d", &E, &F);
        W = F - E;
        dp[0] = 0;
        for (int i = 1; i <= W; ++i) {
            dp[i] = INF;
        }
        scanf("%d", &N);
        for (int i = 1; i <= N; ++i) {
            scanf("%d %d", &e[i].p, &e[i].w);
        }
        DP();
        if (dp[W] == INF) {
            puts("This is impossible.");
        }
        else {
            printf("The minimum amount of money in the piggy-bank is %d.\n", dp[W]);
        }
    }
    return 0;
}