func_code_string: #include <bits/stdc++.h>   using namespace std;   int n, x[1000009], y[1000009], id[1000009];   int main() {     scanf( %d , &n);     for (int i = 1; i <= n; i++) scanf( %d %d , x + i, y + i), id[i] = i;     sort(id + 1, id + 1 + n, [](int a, int b) {       if (x[a] / 1000 != x[b] / 1000) return x[a] / 1000 < x[b] / 1000;       if (x[a] / 1000 % 2) return y[a] > y[b];       return y[a] < y[b];     });     for (int i = 1; i <= n; i++) printf( %d  , id[i]);   }   