Intuition

As the array is already sorted, we can simply scan it linearly to find the target element. This is the most basic approach to search for an element in an array. The search stops as soon as the element is found or the array ends.

Approach

We iterate through the array from the beginning using a for loop and check if the current element matches the target value.

If the target element is found, we break the loop and return the current index.
If the loop completes without finding the element, we return -1 to indicate that the target is not in the array.

Code

#include <bits/stdc++.h>
using namespace std;

// Class to solve linear search problem
class Solution {
public:
    // Function to find first occurrence of target
    int firstOccurrence(vector<int>& arr, int n, int target) {
        // Traverse the array
        for (int i = 0; i < n; i++) {
            // If element matches target return index
            if (arr[i] == target) {
                return i;
            }
        }
        // If not found return -1
        return -1;
    }
};

// Driver code
int main() {
    vector<int> arr = {1, 2, 2, 3, 4, 5};
    int n = arr.size();
    int target = 2;
    Solution obj;
    cout << obj.firstOccurrence(arr, n, target) << endl;
    return 0;
}