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#include <stdio.h>
#include <stdlib.h>
#define NBMAX 80
void acquerir_texte(char *suite, int *nb_car);
void acquerir_cle(int *cle);
char coder_lettre (int cle, char car);
void coder_texte (char *suite, int nb_car,int cle,char *code);
void decoder_texte (char *suite, int nb_car,int cle,char *decode);
void decoder_cle (int *deccle,char *suite,char *code);
void decoder_cle2 (int *deccle,char *suite,char *code);
int main(int argc, char *argv[])
{
char suite_car[NBMAX];
char suite_code[NBMAX],suite_decode[NBMAX];
int nombre_car,serial,i,decserial;
acquerir_texte(suite_car,&nombre_car);
for(i=0;i<nombre_car;i++)
{
printf("%c",suite_car[i]);
}
acquerir_cle(&serial);
coder_texte(suite_car,nombre_car,serial,suite_code);
printf("\n");
printf("Texte code :\n");
for(i=0;i<nombre_car;i++)
{
printf("%c",suite_code[i]);
}
printf("\n");
decoder_texte(suite_code,nombre_car,serial,suite_decode);
printf("\n");
printf("Texte decode :\n");
for(i=0;i<nombre_car;i++)
{
printf("%c",suite_decode[i]);
}
printf("\n");
decoder_cle (&decserial,suite_code,suite_car);
decoder_cle2 (&decserial,suite_code,suite_car);
system("PAUSE");
return 0;
}
void acquerir_texte(char *suite, int *nb_car)
{
int i;
char c;
*nb_car=0;
printf("Entrez votre phrase a coder (Termine par un '.'):\n");
do
{
c=getche();
if (c!= '.')
{
suite[*nb_car]=c;
*nb_car = (*nb_car)+1;
}
}while (c!='.' && (*nb_car)<NBMAX);
printf("\n");
}
void acquerir_cle(int *cle)
{
printf("\nTapez une cle de cryptage: elle doit etre compris entre 0 et 25\n");
do
{
scanf("%d",cle);
if((*cle<0) || (*cle>25))
printf("Erreur! Veuillez recommencer !!!\n");
}while ((*cle<0) || (*cle>25));
printf("Cle de cryptage:%d\n",*cle);
}
char coder_lettre (int cle, char car)
{
int i;
if ((car>='a' && car<='z')||(car>='A' && car<='Z'))
{
for (i=0;i<cle;i++)
{
if((car=='z')||(car=='Z'))
car=car-25;
else car++;
}
}
return (car);
}
void coder_texte (char *suite, int nb_car,int cle,char *code)
{
int i;
for(i=0;i<=nb_car;i++)
code[i]= coder_lettre(cle,suite[i]);
}
void decoder_texte (char *suite, int nb_car,int cle,char *decode)
{
int i;
for(i=0;i<=nb_car;i++)
decode[i]= coder_lettre((26-cle),suite[i]);
}
void decoder_cle (int *deccle,char *suite,char *code)
{
*deccle = suite[0]-code[0];
if(*deccle<0)
*deccle = *deccle+26;
printf("Cle trouve:%d\n",*deccle);
}
void decoder_cle2 (int *deccle,char *suite,char *code)
{
int i;
int lettrecompter[NBMAX];
//Initialisation du tableau
for(i=0;i<=NBMAX-1;i++)
lettrecompter[i]=0;
for(i=0;i<=78;i++)
{
if ((suite[i]>='a') && (suite[i]<='z'))
lettrecompter[suite[i] - 'a']++;
else
{
if(suite[i]>='A' && suite[i]<='Z')
lettrecompter[suite[i] - 'A']++;
}
}
for(i=0;i<=25;i++)
printf("\n%c:%d",'a'+i,lettrecompter[i]);
printf("\n");
} |
