func_code_string: #include <bits/stdc++.h>   using namespace std;   const int Nmax = 1e5 + 5;   const long long inf = 1e18;   int n, k, nr, st[Nmax], A[Nmax], nextBigger[Nmax];   long long dp[Nmax], old[Nmax];   struct Ec {     int a;     long long b;     long long operator()(int x) { return (long long)a * x + b; }   };   Ec interv[Nmax];   class Batch {     vector<Ec> v;     double intersect(Ec A, Ec B) { return (double)(A.b - B.b) / (B.a - A.a); }     bool bad(Ec a, Ec b, Ec c) { return intersect(a, c) >= intersect(a, b); }       public:     void clear() { v.clear(); }     void add(Ec ec) {       while (v.size() >= 2 && bad(v[v.size() - 2], v.back(), ec)) v.pop_back();       v.push_back(ec);     }     long long query(int x) {       if (v.empty()) return inf;       while (v.size() >= 2 && intersect(v[v.size() - 2], v.back()) <= x)         v.pop_back();       return v.back()(x);     }   };   class SegmentTree {     Batch a[Nmax << 2];       public:     void update1(int node, int st, int dr, int pos, Ec ec) {       a[node].add(ec);       if (st == dr) return;       if (pos <= ((st + dr) >> 1))         update1((node << 1), st, ((st + dr) >> 1), pos, ec);       else         update1(((node << 1) | 1), ((st + dr) >> 1) + 1, dr, pos, ec);     }     void update2(int node, int st, int dr, int L, int R, Ec ec) {       if (L <= st && dr <= R) {         a[node].add(ec);         return;       }       if (L <= ((st + dr) >> 1))         update2((node << 1), st, ((st + dr) >> 1), L, R, ec);       if (((st + dr) >> 1) < R)         update2(((node << 1) | 1), ((st + dr) >> 1) + 1, dr, L, R, ec);     }     long long query1(int node, int st, int dr, int L, int R, int p) {       if (L <= st && dr <= R) return a[node].query(p);       long long x = inf, y = inf;       if (L <= ((st + dr) >> 1))         x = query1((node << 1), st, ((st + dr) >> 1), L, R, p);       if (((st + dr) >> 1) < R)         y = query1(((node << 1) | 1), ((st + dr) >> 1) + 1, dr, L, R, p);       return min(x, y);     }     long long query2(int node, int st, int dr, int pos, int p) {       long long x = a[node].query(p);       if (st == dr) return x;       if (pos <= ((st + dr) >> 1))         x = min(x, query2((node << 1), st, ((st + dr) >> 1), pos, p));       else         x = min(x, query2(((node << 1) | 1), ((st + dr) >> 1) + 1, dr, pos, p));       return x;     }     void clear() {       int i;       for (i = 1; i <= ((n + 1) << 2); ++i) a[i].clear();     }   } aint;   void solve() {     int i;     aint.clear();     for (i = n; i >= 0; --i) aint.update1(1, 0, n, i, {-i, old[i]});     nr = 0;     st[0] = 0;     for (i = 1; i <= n; ++i) {       while (nr && A[i] >= A[st[nr]]) --nr;       st[++nr] = i;       interv[i] = {A[i], aint.query1(1, 0, n, st[nr - 1], st[nr] - 1, A[i])};     }     aint.clear();     for (i = n; i >= 1; --i)       aint.update2(1, 0, n, i, nextBigger[i] - 1, interv[i]);     for (i = 1; i <= n; ++i) dp[i] = aint.query2(1, 0, n, i, i);   }   int main() {     int i, j;     cin >> n >> k;     for (i = 1; i <= n; ++i) cin >> A[i];     nr = 0;     st[0] = n + 1;     for (i = n; i; --i) {       while (nr && A[i] > A[st[nr]]) --nr;       nextBigger[i] = st[nr];       st[++nr] = i;     }     old[0] = 0;     for (i = 1; i <= n; ++i) old[i] = inf;     for (i = 1; i <= k; ++i) {       for (j = 1; j <= n; ++j) dp[j] = inf;       dp[0] = 0;       solve();       for (j = 1; j <= n; ++j) old[j] = dp[j];     }     cout << dp[n] <<   n ;     return 0;   }   