quick sort

quick_sort.cpp

#include <utility>
#include <vector>

void quick_sort(std::vector<int>& nums, int l, int r) {
    if (l >= r) {
        return;
    }
    
    // pivot is left
    int tmp = l;
    for (int i = l + 1; i <= r; i++) {
        if (nums[i] < nums[l]) {
            std::swap(nums[++tmp], nums[i]);
        }
    }
    std::swap(nums[tmp], nums[l]);
    
    quick_sort(nums, l, tmp - 1);
    quick_sort(nums, tmp + 1, r);
}

void quick_sort(std::vector<int>& nums) {
    quick_sort(nums, 0, nums.size()-1);
}