i am looking for the right answer for this question, is this correct?

Question

Write a function void switchEnds(int *array, int size); that is passed the address of the beginning of an array and the size of the array. The function swaps the values in the first and last entries of the array.

#include <iostream>
using namespace std;
void switchEnd(int *array, int size){
    int temp=array[0];
    array[0]=array[size-1];
    array[size-1]=temp;
    
}

int main()
{   const int size=5;
    int array[size]={1,2,3,4,5};
    
    switchEnd(array,size);
    
    for (int c=0;c<5;c++)
    cout<<array[c]<<" ";
}

What test cases have you checked? What makes you think this may not be correct (to the point that you'd ask a question here)? — scohe001, Oct 05 '21 at 19:38
Please choose a title which is useful for others with the same problem. — user438383, Oct 05 '21 at 19:40
Would fail with a size zero array, but there isn't much you can do with a size zero array anyway, so I'm not sure it's worth testing for it. The program is probably already broken by that point. — user4581301, Oct 05 '21 at 19:41
If `size==1`, there is no need to go through with swapping -- just return `array[0]`. — PaulMcKenzie, Oct 05 '21 at 19:45
@user4581301 unlike `std::vector`, an array [can not be "size zero"](https://stackoverflow.com/questions/9722632/what-happens-if-i-define-a-0-size-array-in-c-c) — Drew Dormann, Oct 05 '21 at 19:50
@Dara Moustafa Enclose the code of the function in the if statement if ( not ( size < 2 ) ) { /*...*/ } — Vlad from Moscow, Oct 05 '21 at 19:55
@VladfromMoscow `if (size > 1)` would be much cleaner and more readable — Remy Lebeau, Oct 05 '21 at 19:57
Please see: [Why is "Is this correct?" an off topic question, and what should I ask instead?](https://meta.stackoverflow.com/q/359466) — EJoshuaS - Stand with Ukraine, Oct 05 '21 at 21:01

score 0 · Accepted Answer · answered Oct 05 '21 at 20:08

There are multiple ways to do this. Your way is the straight forward way. But the question reminds me of some questions of c++ courses, where you should understand pointers.

If this is the case, then an answer like this might be better:

void switchEnd(int *start, int size){
    int *end = start + size - 1;

    int temp=*start
    *start = *end
    *end = temp
}

Be aware that this solution is not the nice way. It is hard to understand and unhandy. So if you want to implement something like this somewhere in your code, use your solution.

Or better:

void switchEnd(int *array, int size){
    std::swap(array[0], array[size-1]);
}

i am looking for the right answer for this question, is this correct?

1 Answers1