Exercice 15 Série ISI

#include <stdio.h>
#include <stdlib.h>

int main()
{
    int a,b,ab,ba,s;
    do {
        printf ("Donner un nombre strictement positif:\n");
        scanf ("%d",&ab);
    }while (ab<=9  || verif (ab)==0);
    s=ab;
    do {
        ab=s;
        ba=invers(ab);
        s=abs(ab-ba);
        printf ("%d\n",s);
    }while (s!=9);
}


int invers (int ab)
{
    int a,b,s;
    a=(ab/10);
    b=ab%10;
    s=a+(b*10);
    return s;
}

int verif (int ab)
{
    int a,b,s;
    a=(ab/10);
    b=ab%10;
    s=a!=b;
    return s;
}