Recréer la fonction strstr

#include <stdio.h>

#include <stdlib.h>



int Size_String (char *String);

int Comp_String (const char *String_1, const char *String_2);

char *String_In_String (const char *String_1, const char *String_2);



int main(int argc, char *argv [])

 {

     char *Next_String;



     Next_String = String_In_String ("Petit texte de test", "test");



     if (Next_String != NULL)

      {

          printf("L'occurrence est : %s.\n", Next_String);

      }





    return 0;

 }



int Size_String (char *String)

 {

     char Character = 0;

     int Number_Of_Character = 0;



     do

      {

          Character = String [Number_Of_Character];

          Number_Of_Character ++;

      } while(Character != '\0');



    return Number_Of_Character;

 }

int Comp_String (const char *String_1, const char *String_2)

 {

     int Size = 0, Size_1 = 0, Size_2 = 0, Comp = 0, i;



     Size_1 = Size_String (String_1);

     Size_2 = Size_String (String_2);



     Size = Size_1 - Size_2;



     if (Size == 0)

      {

          for(i=0; i<Size; i++)

           {

               if (String_1 [i] == String_2 [i])

                {

                    Comp = 0;

                    //printf("Les chaines sont identiques.\n\n");

                    return Comp;

                }

           }

      }



     else

      {

          if (Size > 0)

           {

               Comp = 1;

               printf("Les chaines sont differentes, la premiere etant plus grande que la seconde.\n\n");

               return Comp;

           }



          if (Size < 0)

           {

               Comp = -1;

               printf("Les chaines sont differentes, la premiere etant plus petite que la seconde.\n\n");

               return Comp;

           }

      }

 }



char *String_In_String (const char *String_1, const char *String_2)

 {

     int Size = 0, Size_1 = 0, Size_2 = 0, Comp = 0, i, k;

     char *Occurrence = 0;



     Size_1 = Size_String (String_1);

     Size_2 = Size_String (String_2);



     Comp = Comp_String (String_1, String_2);



     for(i=0; i<Size_1; i++)

      {

          for(k=0; k<Size_2; k++)

           {

               if ( (String_1 [i] == String_2 [k]))

                {

                    return String_1 - Size_2;

                }

           }

      }



    return NULL;

 }

char* Comp_String (const char* String_1, const char* String_2)

 {

     int Comparaison = 0, Difference = 0;

     int Size_1 = 0, Size_2 = 0, Size = 0, i;



     Size_1 = Size_String (String_1);

     Size_2 = Size_String (String_2);



     Difference = Size_1 - Size_2;



     if (Difference != 0 && Difference > 0)

      {

          Comparaison = 1;

          printf("Les chaines sont differentes.\n");

          printf("La chaine 1 est superieur a la chaine 2.\n");



      }



     else if (Difference != 0 && Difference < 0)

      {

          Comparaison = -1;

          printf("Les chaines sont differentes.\n");

          printf("Le chaine 1 est inferieur a la chaine 2.\n");

      }



     else

      {

          Size = Size_1 = Size_2;

          for(i=0; i<Size; i++)

           {

               if (String_1 [i] == String_2 [i])

                {

                    Comparaison = 0;



                }

           }



          printf("Les chaines sont identiques.\n");

      }



    return Comparaison;

 }

int Comp_String(char *str1, char *str2)

{

	char *P=str1,*Q=str2;

	int comparaison=1;

	while(*P !='\0' || *Q !='\0')

	{

		if(*P!=*Q){comparaison=0;break;}

		P++;Q++;

	}

	return comparaison;



}