采药 水题 dp 01背包问题 luogu1048

最基本的01背包，不需要太多解释，刚学dp的同学可以参见dd大牛的背包九讲，直接度娘“背包九讲”即可搜到

#include <cstdio>
#include <cstring>
#include <algorithm>

const int maxn = 1000 + 500;
int dp[maxn];
int t, m;
int s1, v1;

int main () {
    scanf("%d %d", &t, &m);
    for (int i = 1; i <= m; i++) {
        scanf("%d %d", &s1, &v1);
        for (int j = t; j >= s1; j--) {
            dp[j] = std :: max(dp[j], dp[j - s1] + v1);
        }
    }
    int ans = 0;
    for (int i = 0; i <= t; i++) ans = std :: max(ans, dp[i]);
    printf("%d", ans);
    return 0;
}