vector> dp; vector> C; void rec(int i, int j0, int j1, int k0, int k1) { if (j1 < j0) return; int jmid = (j0 + j1) / 2; dp[i][jmid] = inf; int bestk = k0; for (int k = k0; k < min(jmid, k1 + 1); ++k) { if (dp[i - 1][k] + C[k + 1][jmid] < dp[i][jmid]) { dp[i][jmid] = dp[i - 1][k] + C[k + 1][jmid]; bestk = k; }} rec(i, j0, jmid - 1, k0, bestk); rec(i, jmid + 1, j1, bestk, k1); } ll calc(int n, int k) { dp = vector>(k, vector(n, inf)); for (int i = 0; i < n; i++) dp[0][i] = C[0][i]; for (int i = 1; i < k; i++) { rec(i, 0, n - 1, 0, n - 1); } return dp[k - 1][n - 1]; }