1 #include <iostream>
2 #include <cassert>
3 using namespace std;
4
5 int selectKth(int a[],int start,int end,int k){
6 assert(start <= end && k <= end+1);
7 int left = start;
8 int right = end;
9 int pivotVal = a[left];
10 while(left < right){
11 while(left < right && a[right] >= pivotVal) right--;
12 a[left] = a[right];
13 while(left < right && a[left] <= pivotVal) left++;
14 a[right] = a[left];
15 }
16 a[left] = pivotVal;
17 if(left+1 == k) return a[left];
18 else if(left+1 < k) return selectKth(a,left+1,end,k);
19 else return selectKth(a,start,left-1,k);
20 }
21
22 int main() {
23 int a[10] = {1,3,5,6,7,8,2,4};
24
25 std::cout << selectKth(a,0,7,2) << std::endl;
26 std::cout << selectKth(a,0,7,7) << std::endl;
27
28 return 0;
29 }
