Example: Minimum Sum of Absolute Difference of Pairs in C

// Minimum Sum of Absolute Difference of Pairs
#include <stdio.h>  // For printf
#include <stdlib.h> // For qsort, abs
#include <math.h>   // For fabs (though abs is sufficient for integers)

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

int main() {
    // Step 1: Define two arrays of equal size
    int arrayA[] = {4, 1, 8, 7};
    int arrayB[] = {2, 3, 6, 5};
    int n = sizeof(arrayA) / sizeof(arrayA[0]); // Calculate the size of the arrays

    printf("Original Array A: ");
    for (int i = 0; i < n; i++) {
        printf("%d ", arrayA[i]);
    }
    printf("\n");

    printf("Original Array B: ");
    for (int i = 0; i < n; i++) {
        printf("%d ", arrayB[i]);
    }
    printf("\n\n");

    // Step 2: Sort both arrays using qsort
    // qsort(base, num_elements, size_of_each_element, comparison_function)
    qsort(arrayA, n, sizeof(int), compareIntegers);
    qsort(arrayB, n, sizeof(int), compareIntegers);

    printf("Sorted Array A: ");
    for (int i = 0; i < n; i++) {
        printf("%d ", arrayA[i]);
    }
    printf("\n");

    printf("Sorted Array B: ");
    for (int i = 0; i < n; i++) {
        printf("%d ", arrayB[i]);
    }
    printf("\n\n");

    // Step 3: Calculate the minimum sum of absolute differences
    long long min_abs_diff_sum = 0; // Use long long for sum to prevent overflow

    for (int i = 0; i < n; i++) {
        min_abs_diff_sum += abs(arrayA[i] - arrayB[i]);
    }

    // Step 4: Print the result
    printf("Minimum sum of absolute differences: %lld\n", min_abs_diff_sum);

    return 0;
}