1 //数组a[]中有n各元素，已经按升序排序，待查找的元素x
2 sort(a,a+n); //升序排序
3 template<class Type>
4 int BinarySearch(Type a[],const Type&x,int n)
5 {
6 int left=0; //左边界
7 int right=n-1; //右边界
8 while(left<=right)
9 {
10 int middle=(left+right)/2; //中点
11 if(x==a[middle])return middle; //找到x，返回数组中的位置
12 if(x>a[middle]) left=middle+1;
13 else right=middle-1;
14 }
15 return -1; //未找到x
16 }
17
18
19
20
21
22 #include<iostream>
23 #include<algorithm>
24 using namespace std;
25 bool compare(int a,int b)
26 {
27 return a<b; //升序
28 }
29 template<class Type>int BinarySearch(Type a[],const Type&x,int n)
30 {
31 int left=0;
32 int right=n-1;
33 while(left<=right)
34 {
35 int middle=(left+right)/2;
36 if(a[middle]==x) return middle;
37 if(a[middle]<x) left=middle+1;
38 else right=middle-1;
39 }
40 return -1;
41 }
42 int main()
43 {
44 int a[20];
45 int n,m;
46 cin>>n;
47 for(int i=0; i<n; i++)
48 {
49 cin>>a[i];
50 }
51 sort(a,a+n,compare);
52 for(int i=0; i<n; i++)
53 {
54 cout<<a[i]<<" ";
55 }
56 cout<<endl;
57 m=BinarySearch(a,234,n);
58 cout<<m<<endl;
59 return 0;
60 }
