剑指offer--数字在排序数组中出现的次数

题目描述

统计一个数字在排序数组中出现的次数。

分类：数组

解法1：二分法，找到该数字以后，向两边扩展统计出现的次数

 public class Solution {
     public int GetNumberOfK(int [] array , int k) {
        if(array.length==0) return 0;
         int low = 0;
         int high = array.length-1;
         int mid = (low+high)/2;
         int count = 0;
         while(low<=high){
             mid = (low+high)/2;
             if(array[mid]>k){
                 high = mid-1;
             }else if(array[mid]
                 low = mid+1;
             }else{
                 count = 1;
                 int temp = mid-1;
                 while(temp>=0 && array[temp]==array[mid]){
                     count++;
                     temp--;
                 }
                 temp = mid+1;
                 while(temp
                     count++;
                     temp++;
                 }
                 break;
             }
         }
         return count;
     }
 }

原文链接   http://blog.csdn.net/crazy__chen/article/details/45012893