折半查找

 1 //折半查找
 2 #include<iostream>
 3 #include <algorithm>
 4 using namespace std;
 5 int zheban(int a[], int n, int k)
 6 {
 7     int low = 1, high = n - 1, mid;
 8     while (low<=high)
 9     {
10         mid = (low + high) / 2;
11         if (k==a[mid])
12         {
13             return mid;
14         }
15         if (k<a[mid])
16         {
17             high = mid - 1;
18         }
19         else
20         {
21             low = mid + 1;
22         }
23     }
24     return 0;
25 }
26 int main()
27 {
28     int a[6] = { 5,2,4,3,7,0 };
29     sort(a,a+6);
30     for (auto x : a)
31     {
32         cout << x << " ";
33     }
34     cout << endl;
35     cout << zheban(a, 6, 2);
36     return 0;
37 }