func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 4010;   int n, m, a[N], rt, tot, L[N], siz[N], R[N], ls[N], rs[N];   long long val[N], dp[N][N];   inline void build(int &p, int l, int r) {     if (l > r) return;     p = ++tot;     int pos = l;     for (int i = l; i <= r; ++i)       if (a[i] < a[pos]) pos = i;     val[p] = a[pos];     build(ls[p], l, pos - 1);     build(rs[p], pos + 1, r);     dp[p][0] = 0;     dp[p][1] = m * val[p] - val[p];     siz[p] = 1;     for (int i = siz[p]; i >= 0; --i)       for (int j = 0; j <= siz[ls[p]]; ++j)         dp[p][i + j] =             max(dp[p][i + j], dp[p][i] + dp[ls[p]][j] - 2ll * i * j * val[p]);     siz[p] += siz[ls[p]];     for (int i = siz[p]; i >= 0; --i)       for (int j = 0; j <= siz[rs[p]]; ++j)         dp[p][i + j] =             max(dp[p][i + j], dp[p][i] + dp[rs[p]][j] - 2ll * i * j * val[p]);     siz[p] += siz[rs[p]];   }   int main() {     memset(dp, -0x3f, sizeof(dp));     scanf( %d%d , &n, &m);     for (int i = 1; i <= n; ++i) scanf( %d , &a[i]);     build(rt, 1, n);     printf( %lld n , dp[1][m]);     return 0;   }   