终于AC了（没AC找我）

#include <bits/stdc++.h>
#define MAX 405
using namespace std;
int n, m;
int a[MAX], f[MAX][MAX], s[MAX];
int main(){
    cin >> n >> m;
    for (int i = 1; i <= n; ++i) {
        scanf("%d", &a[i]);
        s[i] = s[i-1]+a[i];
    }
    m++;
    memset(f, 0x3f, sizeof(f));
    f[0][0] = 0;
    for (int i = 1; i <= n; ++i) {
        for (int j = 1; j <= min(m, i); ++j) {
            int mx = a[i];
            for (int k = i-1; k >= 0; --k) {
                f[i][j] = min(f[i][j], f[k][j-1]+mx*(i-k)-(s[i]-s[k]));
                mx = max(mx, a[k]);
            }
        }
    }
    int ans = 0x3f3f3f3f;
    for (int i = 0; i <= m; ++i) {
        ans = min(ans, f[n][i]);
    }
    cout << ans << endl;
    return 0;
}