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Segmentation fault while reversing an array

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cosni -  
mamiemando Posted messages 33540 Registration date   Status Modérateur Last intervention   -

Hello,

I wrote this code to have a function that reverses the order of the elements of an array of integers.

#include <unistd.h> void   ft_rev_int_tab(int *tab, int size) {    int    c;    int    i;    i = 0;    while (i < size / 2)    {       c = tab[i];       i = tab[size - 1 - i];       tab[size - 1 - i] = c;       i++;    } } int main() {    int    p;    int    s;    p = 5;    s = 3;    ft_rev_int_tab(&p,s);    write (1, &p, 1);    return 0; }

Yet, I get this error message and I understand what I need to do to solve this problem:

 - [1] + 5608 suspended cat - [1] 5252 segmentation fault ./a.out

Can you help me please? Thank you!

3 réponses

Réponse 1 / 3
Anonymous user
 

Hello
For your next messages, please use syntax highlighting as described here

For your problem, your function expects an array of int. You are not providing it

When I was little, the Dead Sea was just sick.
George Burns
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Réponse 2 / 3
PierrotLeFou
 

This is not the only problem. Your way of swapping two values is not correct. The variable i has a double use ...

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Réponse 3 / 3
mamiemando Posted messages 33540 Registration date   Status Modérateur Last intervention   7 927
 

Hello,

As Pierrot rightly pointed out in his message #2, your variable i has a dual role:

  • sometimes one of the two indices where the swap occurs,
  • sometimes a value from the array (which in general is outside the valid index range of the array, and thus leads to a segmentation fault).

Furthermore, your way of declaring your array is a bit convoluted.

To solve all these issues, you could take inspiration from this link.

Good luck
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