LA 8044. ACM-ICPC World Finals 2017 F. Posterize

线性动态规划

#include <iostream>
#include <algorithm>
#include <cstring>

int main() {
  int d, k;
  std::cin >> d >> k;
  int r[257], p[257];
  for (int i = 1; i <= d; i++)
    std::cin >> r[i] >> p[i];
  
  static long long f[257][257];
  memset(f, 0x7f, sizeof(f));
  for (int v = 0; v < 256; v++)
    for (int i = 1; i <= d; i++) {
      long long sum_of_squared_errors = 0;
      for (int j = i; j <= d; j++) {
        sum_of_squared_errors += 1LL * (r[j] - v) * (r[j] - v) * p[j];
        f[i][j] = std::min(f[i][j], sum_of_squared_errors);
      }
    }
  
  static long long c[257][257];
  memset(c, 0x7f, sizeof(c));
  c[0][0] = 0;
  for (int i = 1; i <= d; i++) {
    for (int j = 1; j <= std::min(i, k); j++) {
      for (int s = 0; s < i; s++)
        c[i][j] = std::min(c[i][j], c[s][j - 1] + f[s + 1][i]);
    }
  }
  
  std::cout << c[d][k] << std::endl;
  return 0;
}