Leetcode binary Search Insert Position

 

 

 

Search Insert PositionTotal Accepted: 14279 Total Submissions: 41575

 

Given a sorted array and a target value, return the index if the target is found. If not, return the index where it wocould 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

Output the position of an element in a sorted array. If no position exists, it should be inserted.
Idea: Perform binary search. if it finds the output location, the output location should be inserted if it cannot be found.
Complexity: time O (log n), Space O (1)

 

Related questions:

Search for a Range

Search a 2D Matrix

 

Class Solution {public: int searchInsert (int A [], int n, int target) {int s = 0, e = n-1, m; // intermediate number, when there are even numbers, take the first while (s <= e) {m = (s + e)/2; if (A [m] = target) return m; if (A [m] <target) s = m + 1; if (A [m]> target) e = m-1;} if (A [m]> target) return m; else return m + 1 ;}};