func_code_string: #include <bits/stdc++.h>   int x, k;   int NumsBetween(int a, int b) { return (b / x - (a - 1) / x); }   int main() {     int n;     std::cin >> n >> x >> k;     std::vector<int> array(n, 0);     for (int i = 0; i < n; ++i) {       std::cin >> array[i];     }     std::sort(array.begin(), array.end());     long long answ = 0;     int pointer = 0;     int start = 0;     int finish = 0;     while (pointer < n) {       for (; start < n; start += 1) {         if (NumsBetween(array[pointer], array[start]) >= k) break;       }       for (; finish < n; finish += 1) {         if (NumsBetween(array[pointer], array[finish]) > k) break;       }       answ += finish - start;       pointer += 1;       if (start != n && pointer != n && array[pointer] > array[start])         start = pointer;       if (finish != n && start != n && array[start] > array[finish])         finish = start;     }     std::cout << answ << std::endl;     return 0;   }   