C Program for product of array

Given an array arr[n] of n number of elements, the task is to find the product of all the elements of that array.

Like we have an array arr[7] of 7 elements so its product will be like −

Syntax

int productOfArray(int arr[], int n);

Example: Input and Output

Input: arr[] = { 10, 20, 3, 4, 8 }
Output: 19200
Explanation: 10 × 20 × 3 × 4 × 8 = 19200

Input: arr[] = { 1, 2, 3, 4, 3, 2, 1 }
Output: 144

Algorithm

• Initialize a variable result to 1
• Iterate through each element of the array
• Multiply each element with the result
• Return the final result

Example: Product of Array Elements

#include <stdio.h>

int prod_arr(int arr[], int n) {
    int result = 1;
    // Multiply each element and store it in result
    for (int i = 0; i < n; i++) {
        result = result * arr[i];
    }
    return result;
}

int main() {
    int arr[] = { 10, 20, 3, 4, 8 };
    int n = sizeof(arr) / sizeof(arr[0]);
    printf("Product of array elements: %d<br>", prod_arr(arr, n));
    return 0;
}

Product of array elements: 19200

Key Points

• Initialize the result variable to 1, not 0, since multiplying by 0 gives 0
• The time complexity is O(n) where n is the number of elements
• Space complexity is O(1) as only one extra variable is used

Conclusion

Finding the product of array elements is straightforward using a simple loop. Initialize the result to 1 and multiply each element sequentially to get the final product.