快速排序
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
1 #include <iostream> 2 #include <cstdio> 3 using namespace std; 4 int a[100]; 5 void qsort(int *s,int *e) 6 { 7 if (s>=e) return; 8 int mid = *(s+(e-s)/2); 9 int * l = s; 10 int * r = e; 11 int i = 0; 12 while (l<r) 13 { 14 while ((*l)<mid&&l<=r) l++; 15 while ((*r)>mid&&l<=r) r--; 16 if (l<=r) 17 { 18 int t = *(l); 19 *l = *r; 20 *r = t; 21 l++;r--; 22 } 23 } 24 qsort(l,e); 25 qsort(s,r); 26 return; 27 } 28 int main() 29 { 30 int n = 0 ; 31 cin >> n; 32 for (int i = 0; i< n ;i++) cin >> a[i]; 33 34 qsort(a,a+n-1); 35 36 for (int i = 0; i<n ;i++) 37 cout <<a[i]<<" "; 38 cout <<endl; 39 return 0; 40 }