Question

[ Write in C not C++]

Define a C function void placeElements(int *a, int i, int j) that
inter-exchange the array elements at indexiandj. For a[] = {5,7,4,2,1},a
callto placeElements(a,2,4) makesa[] = {5,7,1,2,4}. [8]

Answer 1

#include <stdio.h>

void placeElements(int *a, int i, int j);

int main() {
    int a[] = {5, 7, 4, 2, 1}, i;
    for (i = 0; i < 5; ++i) {
        printf("%d ", a[i]);
    }
    printf("\n");
    placeElements(a, 2, 4);
    for (i = 0; i < 5; ++i) {
        printf("%d ", a[i]);
    }
    printf("\n");
    return 0;
}

void placeElements(int *a, int i, int j) {
    int temp = a[i];
    a[i] = a[j];
    a[j] = temp;
}