DSA/algorithms/CPlusPlus/Arrays/search-insert-position.cpp

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/*
Description: Given a sorted array of distinct integers 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.
Approach: Using Binary search to solve in least time complexity.
Time Complexity: O(log n)
*/
#include <iostream>
#include <vector>
using namespace std;
//function
int searchInsert(vector<int>& nums, int target) {
//starting index
int start=0;
//ending index
int end=nums.size()-1;
while(start<=end){
//calculating mid element
int mid = start + (end-start)/2;
//if target found, return the index
if(nums[mid]==target){
return mid;
}
if(nums[mid]>target){
end=mid-1;
}
else{
start=mid+1;
}
}
//returning end+1 so that we can get the index where the target element can be inserted
return end+1;
}
//main starts
int main() {
cout << "Enter number of elements in the array\n";
int n;
cin>>n;
cout<<"Enter the array elements\n";
vector<int> nums(n);
for(int i=0;i<n;i++){
cin>>nums[i];
}
cout<<"Enter the target element\n";
int target;
cin>>target;
cout<<"The target element can be inserted at: "<<searchInsert(nums,target);
return 0;
}
/*
Example 1
Input: nums = [1,3,5,6], target = 5
Output: 2
(Since the target element is present it will return its index)
Example 2:
Input: nums = [1,3,5,6], target = 2
Output: 1
(Since the target element is not present in the nums array, it will return the position where the target element can be inserted)
We can insert 2 at position 1 - [1,2,3,5,6]
*/