/**
* Source : https://oj.leetcode.com/problems/search-insert-position/
*
* Created by lverpeng on 2017/7/14.
*
* Given a sorted array and a target value, return the index if the target is found.
* If not, return the index where it would be if it were inserted in order.
*
* You may assume no duplicates in the array.
*
* Here are few examples.
* [1,3,5,6], 5 → 2
* [1,3,5,6], 2 → 1
* [1,3,5,6], 7 → 4
* [1,3,5,6], 0 → 0
*
*/
public class SearchInsertPosition {
/**
* 二分查找
*
* @param num
* @param target
* @return
*/
public int binarySearch (int[] num, int target) {
int left = 0;
int right = num.length - 1;
int mid = 0;
while (left <= right) {
mid = (left + right) / 2;
if (num[mid] == target) {
return mid;
}
if (target > num[mid]) {
left = mid + 1;
} else {
right = mid - 1;
}
}
return left;
}
public static void main(String[] args) {
SearchInsertPosition searchInsertPosition = new SearchInsertPosition();
int[] arr = new int[]{1,3,5,6};
System.out.println(searchInsertPosition.binarySearch(arr, 5));
System.out.println(searchInsertPosition.binarySearch(arr, 2));
System.out.println(searchInsertPosition.binarySearch(arr, 7));
System.out.println(searchInsertPosition.binarySearch(arr, 0));
}
}