Search Insert Position

Search Insert Position

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

class Solution {//cheating method
public:
    int searchInsert(int A[], int n, int target) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        int* low = lower_bound(A,A+n,target);
        return low-A;
    }
};

//binary method

class Solution {
    int process(int A[], int start, int end, int target){
        if (start == end){
            if (target > A[start]) return start+1;
            else return start;
        }
        int half = start + (end-start)/2;
        if (target <= A[half]) return process(A, start, half, target);
        else return process(A, half+1, end, target);
    }
public:
    int searchInsert(int A[], int n, int target) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        return process(A, 0, n-1, target);
    }
};