简介： ?二分查找算法是针对有序数组进行查找某个元素的算法，时间复杂度为Ο(logn)?。
public int search(int[] arr,int x) throws Exception{
int start = 0;
int end = arr.length-1;
while(start<=end){
int mid = (start+end)/2;
if(arr[mid]>x){
end = mid-1;
}else if(arr[mid] == x){
return mid;
}else if(arr[mid]<x){
start = mid+1;
}
}
throw new Exception("not found"+x);
}
?原文：http://haoran-10.iteye.com/blog/2267250