Search Insert Position

容易 搜索插入位置

29%

通过

给定一个排序数组和一个目标值，如果在数组中找到目标值则返回索引。如果没有，返回到它将会被按顺序插入的位置。

你可以假设在数组中无重复元素。

您在真实的面试中是否遇到过这个题？

Yes

样例

[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 Solution {
    public int searchInsert(int[] nums, int target) {
        int low = 0;
        int high = nums.length-1;
        while(low < high){
            int mid = low + (high - low)/2;
            if(target > nums[mid]){
                low = mid + 1;
            }else if(target < nums[mid]){
                high = mid -1;
            }else{
                return mid;
            }
        }
        if(target > nums[low]){
            return low+1;
        }else{
            return low;
        }
        
    }
}

lintcode:

public class Solution {
    /** 
     * param A : an integer sorted array
     * param target :  an integer to be inserted
     * return : an integer
     */
    public int searchInsert(int[] A, int target) {
        int start = 0;
        int end = A.length - 1;
        int mid;
        
        if(A==null || A.length == 0){
            return 0;
        }
        if (target < A[0]) {
            return 0;
        }
        // find the last number less than target
        while (start + 1 < end) {
            mid = start + (end - start) / 2;
            if (A[mid] == target) {
                return mid;
            } else if (A[mid] < target) {
                start = mid;
            } else {
                end = mid;
            }
        }
        //target一共有4种大小，=start,>start,=end,>end
        if (A[end] < target) {
            return end + 1;
        }
        if (A[end] == target) {
            return end;
        }
        if (A[start] < target) {
            return start + 1;
        }
        return start;
    }
}