二分查找

private static int searchIdex(int[] arr, int target) {
int left = 0;
int right = arr.length - 1;
int mid;

int count=0;
while (left <= right) {<br />        count++;<br />        //mid = (left + right) / 2;<br />        mid=(left + right)>>>1;<br />        mid=left-(left-right)/2;<br />        if (arr[mid] == target) {<br />            System._out_.println("次数"+count);<br />            return mid;<br />        } else if (arr[mid] < target) {<br />             left=mid+1;<br />        }else {<br />            right =mid-1;<br />        }<br />    }<br />    return -1;<br />}