#include <stdio.h>
#include <stdlib.h>
 
void mswap(int* array, size_t size)
{
    int i, j, tmp;
    for(i=0,j=((size+(size&1))/2);j<size;++i,++j)
    {
        tmp = array[i];
        array[i] = array[j];
        array[j] = tmp;
    }
}
 
void displ(int* array, size_t size)
{
    int i;
    for(i=0;i<size;++i)
        printf("%d - ", array[i]);
    printf("\n");
}
 
int main()
{
    int tab1[4] = {1, 2, 3, 4}, tab2[5] = {1, 2, 3, 4, 5};
    mswap(tab1, 4), mswap(tab2, 5);
    displ(tab1, 4), displ(tab2, 5);
    return 0;
}

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