File size: 1,547 Bytes
bff4ec7 3805fe5 bff4ec7 3805fe5 bff4ec7 3805fe5 bff4ec7 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 | 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;
}
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