java折半查找（正常的折半查找） 

 1 import java.util.Scanner;
 2 
 3 /**
 4  * @author Administrator 折半查找
 5  */
 6 public class zhebansousuo {
 7 
 8     public static void main(String[] args) {
 9         int[] a = new int[100];
10         int x, b;
11         Scanner cin = new Scanner(System.in);
12         x = cin.nextInt();
13 
14         for (int i = 0; i < x; i++) {
15             a[i] = cin.nextInt();
16         }
17         b = cin.nextInt();
18         System.out.println(sea(a, b, 0, x));
19 
20     }
21 
22     public static int sea(int[] a, int x, int beg, int last) {
23         int mid;
24         if (beg > last) {
25             return -1;
26         }
27         while (beg <= last) {
28             mid = (beg + last) / 2;
29             if (x == a[mid]) {
30                 return mid;
31             } else if (a[mid] < x) {
32                 beg = mid + 1;
33             } else if (a[mid] > x) {
34                 last = mid - 1;
35             }
36         }
37         return -1;
38     }
39 
40 }
折半查找

 

posted @ 2013-12-10 22:41  天天AC  阅读(293)  评论(0)    收藏  举报