1186: 二分搜索

Memory Limit:128 MB Time Limit:1.000 S
Judge Style:Text Compare Creator:
Submit:25 Solved:15

Description

已知有n个升序排序的正整数, 10 <= n <= 100,000,且这n个数字<=10,000,000
现要求在这n个数字中查找指定数字m,并返回m是第几个数字,若找不到m则返回-1

Input

第一行两个数字n, m, 10 <= n <= 100,000,  0 < m <= 10,000,000
接下来n个正整数,升序排列

Output

m是第几个数字

Sample Input Copy

10  25
3
4
6
25
26
32
37
44
53
55

Sample Output Copy

4

Source/Category