TheAlgorithms-C/misc/mirror.c

58 lines
1.3 KiB
C

#include <stdio.h>
#include <string.h> // we include the library string.h to the use of string
void saisie (char *cpointeur); // Prototypes of the three functions used in the program
int compte (char *s);
char* miroir (char * s);
int main (int argc , char *argv[])
{
char chaine[20];
saisie(chaine);
printf("miroir est %s",miroir(chaine));
}
// this function is used to put a string
void saisie (char *cpointeur)
{
printf("saisir une chaine\n");
scanf("%s",cpointeur);
}
/* the function miroir (in french ) it means "mirror" , the major idea is to permute the first caractere with the last using an auxilary
variable (aux) the the 2nd character with the penultimate one and so on .
we made a call to the function (compte) which counts the length of the string . As you can see clearly , I substruct 1 from the equation
k = compte(s)-1 ; to get rid of the EOF caractere which is '\0' because it is not a caractere from the string typed */
char* miroir (char *s)
{
int i ;
char aux ;
int k ;
k = compte(s)-1 ;
i = 0 ;
while(i<=k)
{
aux = s[i];
s[i]=s[k];
s[k]=aux ;
k-- ;
i++ ;
}
return s ;
}
// compte plays the role of strlen so we can change it by an strlen function if you want that
int compte (char *s)
{
char *p ;
int k ;
p=s ;
k=0 ;
while(*p!='\0')
{
p++ ;
k++ ;
}
return k ;
}