Question

I hope you can help. I am trying to write a program that ‘given a list(array) of 10 integers, find the one with the smallest absolute value and swap its position with the last one and output the new list.

Here’s what I have coded but its not swaping..

#include stdio.h
#include math.h

int main() {

    int array[10];
    int arraynew[10];
    int absmallest = 0;
    int index = 0;
    int i;
    for (i = 0; i < 10; i++) {
        scanf("%d", &array[i]);
    }
    absmallest = array[0];

    for (i = 0; i < 10; i++) {
        if (abs(array[i]) < absmallest)
            absmallest = array[i];
        index = i;
    }

    int temp;
    temp = array[9];
    array[9] = array[index];
    array[index] = temp;

    for (i = 0; i < 10; i++) {
        printf("%d", array[i]);
    }
}

Answer 1

You need to update your index inside the if-statement.

if (abs(array[i]) < absmallest)
    absmallest = array[i];
index = i;

should be

if (abs(array[i]) < absmallest)
{
    absmallest = array[i];
    index = i;
}

Otherwise, you update your index on each loop.

---

EDIT: As @amit noted, you also need to store the absolute value, not the real one. In other words

absmallest = array[i];

should be

absmallest = abs( array[i] );

And the same for the initialization of absmallest

absmallest = abs( array[0] );