Answer to Question #256268 in C for Amit

Question

Two arrays are given. Write the C code to swap elements from each array such that after

swapping, sum of elements of array1=sum of elements of array2..

Example:

Array 1: 3, 2, 10, 12

Array 2: 6, 4, 9, 10

After swapping 3 (from Array 1) with 4 (from Array 2)

Array1: 4, 2, 10, 12 Sum = 28

Array2: 6, 3, 9, 10 Sum = 28

Answer 1

#include <stdio.h>

void print_array(int a[], int n, char* str) {
    int i;


    printf(str);
    for (i=0; i<n; i++) {
        printf("%d ", a[i]);
    }
    printf("\n");
}

int sum_array(int a[], int n) {
    int i;
    int s = 0;
    
    for (i=0; i<n; i++) {
        s += a[i];
    }
    return s;
}

int swap(int a1[], int m, int a2[], int n) {
    int dif;
    int i, j, tmp;
    
    dif = sum_array(a1, n) - sum_array(a2, n);
    for (i=0; i<m; i++) {
        for (j=0; j<n; j++) {
            if (a1[i] - a2[j] == dif/2) {
                tmp = a1[i];
                a1[i] = a2[j];
                a2[j] = tmp;
                return 1;
            }
        }
    }
    return 0;
}

int main() {
    int a1[] = { 3, 2, 10, 12};
    int a2[] = { 6, 4, 9, 10};
    int m = sizeof(a1) / sizeof(a1[0]);
    int n = sizeof(a2) / sizeof(a2[0]);

    print_array(a1, m, "Array1: ");
    print_array(a2, n, "Array2: ");

    printf("\nSwapping\n");
    if (swap(a1, m, a2, n)) {
        print_array(a1, m, "Array1: ");
        printf("Summ is %d\n", sum_array(a1, m));
        print_array(a2, n, "Array2: ");
        printf("Summ is %d\n", sum_array(a2, n));
    }
    else {
        printf("Sorry, can't do that\n");
    }
}