传送门:https://vjudge.net/problem/20465/origin
题意：你有n种钞票，面值为c[i],数量为v[i]，便利店老板有无数张面值为c[i]的钞票，问你买一个价值为T的物品，最少需要经手多少张钞票，老板找零的钞票数也算经手的钞票数
题解：因为我的钞票是有限的，所以将自己看作一个多重背包，老板的钞票是无限的，所以将老板的钞票看做一个完全背包，定义状态dp[i]最少花费多少张钞票可以买价值为i的物品
边界：dp[0]=0;
目的：ans=min(dp1[i]+dp2[i-v]) i>=v;
代码：
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