35. Search Insert Position

35. Search Insert Position (Easy)

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.

Example 1:

Input: [1,3,5,6], 5
Output: 2

Example 2:

Input: [1,3,5,6], 2
Output: 1

Example 3:

Input: [1,3,5,6], 7
Output: 4

Example 4:

Input: [1,3,5,6], 0
Output: 0

Related Topics:
Array, Binary Search

Similar Questions:

• First Bad Version (Easy)

Solution 1. Binary Search

// OJ: https://leetcode.com/problems/search-insert-position/
// Author: github.com/lzl124631x
// Time: O(logN)
// Space: O(1)
class Solution {
public:
    int searchInsert(vector<int>& A, int target) {
        int L = 0, R = A.size() - 1;
        while (L <= R) {
            int M = (L + R) / 2;
            if (A[M] == target) return M;
            if (A[M] < target) L = M + 1;
            else R = M - 1;
        }
        return L;
    }
};