void swap(int *arr, int i, int j) { int tmp = arr[i]; arr[i] = arr[j]; arr[j] = tmp; } int partition(int *arr, int n, int low, int high) { int pivot = arr[high]; int i = low - 1; for (int j = low; j < high; j++) { if (arr[j] <= pivot) { i++; swap(arr, i, j); } } swap(arr, i + 1, high); return i + 1; } void quicksort_range(int *arr, int n, int left, int right) { if (left < right) { int p = partition(arr, n, left, right); if (p > left) { quicksort_range(arr, n, left, p - 1); } if (p < right) { quicksort_range(arr, n, p + 1, right); } } } void int_array_quicksort(int *arr, int n) { quicksort_range(arr, n, 0, n - 1); } int discretize(const int *src, int n, int *dest_map) { for (int i = 0; i < n; i++) { dest_map[i] = src[i]; } int_array_quicksort(dest_map, n); int slow = 0; for (int fast = 1; fast < n; fast++) { if (dest_map[fast] != dest_map[slow]) { slow++; dest_map[slow] = dest_map[fast]; } } return slow + 1; } int query_forward(const int *map, int map_size, int target) { int low = 0; int high = map_size - 1; while (low <= high) { int mid = low + (high - low) / 2; if (map[mid] == target) { return mid; } else if (map[mid] < target) { low = mid + 1; } else { high = mid - 1; } } return -1; }