HDU 1114 Piggy-Bank——完全背包

来源：互联网发布：淘宝一颗钻要刷多少单编辑：程序博客网时间：2024/06/05 00:50

O(VN)的完全背包，注意题目限制条件：物品总cost恰好达到V，一开始还优化了一下，把val小cost大的物品去掉了，后来一想这样会产生错误的结果

#include <cstdio>#include <cstring>#include <iostream>#include <algorithm>using namespace std;const int INF = 0x3f3f3f3f;const int MAXN = 500 + 10;const int MAXV = 10000 + 10;int T, N, V, dp[MAXV];struct Item {    int val, cost;}item[MAXN];int main() {    scanf("%d", &T);    for (int kase = 1; kase <= T; kase++) {        int a, b; scanf("%d %d", &a, &b); V = b - a;        scanf("%d", &N);        for (int i = 1; i <= N; i++) {            scanf("%d %d", &item[i].val, &item[i].cost);        }        for (int i = 1; i <= V; i++) dp[i] = INF;        for (int i = 1; i <= N; i++) {            for (int j = item[i].cost; j <= V; j++) {                dp[j] = min(dp[j], dp[j - item[i].cost] + item[i].val);            }        }        if (dp[V] == INF) printf("This is impossible.\n");        else {            printf("The minimum amount of money in the piggy-bank is %d.\n", dp[V]);        }    }    return 0;}

阅读全文

1 0