排序数组搜索某个元素，这种思维一定要往二分法上靠

public class searchInsertPosition{public static void main(String[] args) {int arr[] = {1,3,5,6};System.out.println(getIndex(arr,2));}public static int getIndex(int[] arr,int target) {int start = 0;int end = arr.length - 1;while(start <= end) {int mid = (start + end) / 2;if(arr[mid] == target) {return mid;}if(arr[mid] < target) {start = mid + 1;} else {end = mid - 1;}}return start;}
}