原题链接:
http://acm.hdu.edu.cn/showproblem.php?pid=1114
题目大意:
给定一个存钱罐的空时的重量E和满时的重量F,再给n种类型的钱币(无限多),之后给出钱币的价值和重量。
求存钱罐装满时最少存多少价值的钱。
dp数组初始化为INF(注意dp[ 0 ]除外)。
状态转移方程:
dp[ j ] = min(dp[ j ], dp[ j - w[i] ] + p[ i ]);
代码如下:
#include<iostream>
#include<algorithm>
#include<cstring>
using namespace std;
const int INF = (1 << 30);
const int N = 500 + 10;
int p[N], w[N];
int dp[10000 + 10];
int main()
{
int T;
cin >> T;
while (T--)
{
int E, F;
int n;
cin >> E >> F >> n;
for (int i = 1; i <= n; i++)
cin >> p[i] >> w[i];
int full = F - E; //求出能盛钱的重量
for (int i = 1; i <= full; i++) dp[i] = INF;
for (int i = 1; i <= n; i++)
{
for (int j = w[i]; j <=full; j++)
dp[j] = min(dp[j], dp[j - w[i]] + p[i]);
}
if (dp[full] == INF)cout << "This is impossible."<<endl;
else cout <<"The minimum amount of money in the piggy-bank is "<< dp[full]<<'.' << endl;
}
return 0;
}