Example: Find Second Smallest by Sorting in C

// Find Second Smallest by Sorting
#include <stdio.h>
#include <stdlib.h> // Required for qsort

// Comparison function for qsort
int compare(const void *a, const void *b) {
    return (*(int*)a - *(int*)b);
}

int main() {
    int arr[] = {5, 2, 8, 1, 9, 2}; // Example array with duplicates
    int n = sizeof(arr) / sizeof(arr[0]);

    // Step 1: Handle edge cases for array size
    if (n < 2) {
        printf("Array size must be at least 2 to find the second smallest element.\n");
        return 1;
    }

    // Step 2: Sort the array using qsort
    qsort(arr, n, sizeof(int), compare);

    // Step 3: Find the second smallest unique element
    int firstSmallest = arr[0];
    int secondSmallest = -1; // Initialize with a value indicating not found

    for (int i = 1; i < n; i++) {
        if (arr[i] > firstSmallest) {
            secondSmallest = arr[i];
            break; // Found the first element greater than the smallest
        }
    }

    if (secondSmallest != -1) {
        printf("The array is: ");
        for (int i = 0; i < n; i++) {
            printf("%d ", arr[i]);
        }
        printf("\nThe second smallest element is: %d\n", secondSmallest);
    } else {
        printf("No second smallest element found (all elements might be the same).\n");
    }

    return 0;
}