Files
algo2025/sort_closet/code-sorting/DualPivotQuickSort.cpp
2025-12-18 16:00:22 +08:00

68 lines
2.0 KiB
C++

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
void dualPivotQuickSortHelper(vector<int>& nums, int left, int right, long long& comp_count, long long& move_count) {
if (left < right) {
comp_count++;
if (nums[left] > nums[right]) {
swap(nums[left], nums[right]);
move_count += 3;
}
int p = nums[left], q = nums[right];
int l = left + 1, g = right - 1, k = l;
while (k <= g) {
comp_count++;
if (nums[k] < p) {
swap(nums[k], nums[l]);
move_count += 3;
l++;
} else {
comp_count++;
if (nums[k] > q) {
while (k < g && (comp_count++, nums[g] > q)) {
g--;
}
swap(nums[k], nums[g]);
move_count += 3;
g--;
comp_count++;
if (nums[k] < p) {
swap(nums[k], nums[l]);
move_count += 3;
l++;
}
}
}
k++;
}
l--;
g++;
swap(nums[left], nums[l]);
move_count += 3;
swap(nums[right], nums[g]);
move_count += 3;
dualPivotQuickSortHelper(nums, left, l - 1, comp_count, move_count);
dualPivotQuickSortHelper(nums, l + 1, g - 1, comp_count, move_count);
dualPivotQuickSortHelper(nums, g + 1, right, comp_count, move_count);
}
}
/*
* function : implement dual pivot quick sort
* param nums : the vector to be sorted
* param comp_count : count of comparisons
* param move_count : count of moves
* return : ---
*/
void DualPivotQuickSort(vector<int>& nums, long long& comp_count, long long& move_count) {
if (nums.empty()) return;
dualPivotQuickSortHelper(nums, 0, nums.size() - 1, comp_count, move_count);
}