Method cmp

code/data-structures/kd_tree.cpp:13–13

  struct cmp {
    int c;
    cmp(int _c) : c(_c) {}
    bool operator ()(const pt &a, const pt &b) const {
      for (int i = 0, cc; i <= K; i++) {
        cc = i == 0 ? c : i - 1;