#include <iostream>
#include <vector>
#include <stack>
#include <memory.h>
#include <unordered_map>
#include <queue>
#include <functional>
template<class T>
using compare = int(*)(const T&a, const T&b);
template<class T>
int my_compare(const T&a, const T&b) {
return a <= b? -1: 1;
}
template<class T>
int my_partition(std::vector<T>& a, int low, int high, compare<T> f) {
T flag = a[low];
while (low < high) {
while (low < high && f(flag, a[high]) <= 0) high--;
a[low] = a[high];
while (low < high && f(flag, a[low]) >= 0) low++;
a[high] = a[low];
}
std::cout << flag << " " << a[low] << std::endl;
a[low] = flag;
return low;
}
template<class T>
void my_sort(std::vector<T>& a, int low, int high, compare<T> f) {
if (low >= high) {
return;
}
int mid = my_partition(a, low, high, f);
my_sort(a, low, mid-1, f);
my_sort(a, mid+1, high, f);
}
template<class T>
void my_sort(std::vector<T>& a, compare<T> f) {
my_sort(a, 0, a.size()-1, f);
}
int main() {
std::vector<int> a = {31,12,12,34,1};
my_sort(a, my_compare);
for (int i = 0; i < 5; i++) {
std::cout << a[i] << ",";
}
std::cout << std::endl;
// int a[] = {1,2,3};
// perm(a, 0, 3);
return 0;
} 