非递归快排
2020-04-15 本文已影响0人
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#include <iostream>
#include <vector>
#include <stack>
using namespace std;
void quick_sort(vector<int> &v){
int left = 0, right = v.size() - 1;
stack<pair<int, int> >s;
s.push(make_pair(left, right));
while (!s.empty()){
pair<int, int> t = s.top();
s.pop();
int left = t.first;
int right = t.second;
if (right <= left){
continue;
}
int i = left, j = right;
int target = v[left];
while (i < j){
while (i < j && v[j] >= target){
j--;
}
while (i < j && v[i] <= target){
i++;
}
if (i != j){
swap(v[i], v[j]);
}
}
v[left] = v[i];
v[i] = target;
if (left <= i - 1){
s.push(make_pair(left, i - 1));
}
if (i + 1 <= right){
s.push(make_pair(i + 1, right));
}
}
}
int main(){
int n, t;
vector<int> v;
cin >> n;
for (int i = 0; i < n; i++){
cin >> t;
v.push_back(t);
}
quick_sort(v);
for (int i = 0; i < v.size(); i++){
cout << v[i] << " ";
}
}