Data Structure & Algorithms
DSA
Introduction to arrays
Linear Search Multiple Occurences

# Linear Search - Multiple Occurences

## Problem Description

Given an array A and an integer B, find the number of occurrences of B in A.

### Problem Constraints

``````1 <= B, Ai <= 10^9
1 <= |A| <= 10^5``````

### Input Format

``Given an integer array A and an integer B.``

### Output Format

``Return an integer, number of occurrences of B in A.``

### Example Input

``````Input 1:
A = [1, 2, 2], B = 2

Input 2:
A = [1, 2, 1], B = 3``````

### Example Output

``````Output 1:
2

Output 2:
0 ``````

### Example Explanation

``````Explanation 1:
Element at index 2, 3 is equal to 2 hence count is 2.

Explanation 2:
There is no element equal to 3 in the array.``````

### Output

Java
``````public class Occurrences {
public static int countOccurrences(int[] A, int B) {
int count = 0;
for (int value : A) {
if (value == B) {
count++;
}
}
return count;
}

public static void main(String[] args) {
int[] arr1 = {1, 2, 2};
int val1 = 2;
System.out.println(countOccurrences(arr1, val1)); // Output: 2

int[] arr2 = {1, 2, 1};
int val2 = 3;
System.out.println(countOccurrences(arr2, val2)); // Output: 0
}
}``````
Python
``````def count_occurrences(A, B):
return A.count(B)

# Test cases
arr1 = [1, 2, 2]
val1 = 2
print(count_occurrences(arr1, val1))  # Output: 2

arr2 = [1, 2, 1]
val2 = 3
print(count_occurrences(arr2, val2))  # Output: 0``````
JavaScript
``````function countOccurrences(A, B) {
return A.filter(val => val === B).length;
}

// Test cases
const arr1 = [1, 2, 2];
const val1 = 2;
console.log(countOccurrences(arr1, val1)); // Output: 2

const arr2 = [1, 2, 1];
const val2 = 3;
console.log(countOccurrences(arr2, val2)); // Output: 0``````