vigenere.c

#include "vigenere.h"

char char_valid(char c)
{
    return c >= charmin && c <= charmax;
}

unsigned short char2short(char c)
{
    return c - charmin;
}

char short2char(unsigned short c)
{
    return c + charmin;
}

void codageVigenere(const char* src, char* dest, const char* clef, vigenere codage)
{
    const int num_chars = charmax - charmin + 1;
    const char* k = clef;

    for (const char* p = src; *p; p++)
    {
        *dest++ = char_valid(*p)
                ? short2char(((short)(char2short(*p) - (2 * codage - 1) * char2short(*k)) % num_chars + num_chars) % num_chars)
                : *p;

        if (!*++k)
            k = clef;
    }

    *dest = 0;
}

pascal.c

#include <stdio.h>
#include <string.h>
#include "pascal.h"

void afficheTPascal(unsigned char rang)
{
    rang++;
    int pascal[rang];
    memset(pascal, 0, rang * sizeof(int));
    pascal[0] = 1;

    for (unsigned char i = 1; i < rang; i++)
    {
        for (unsigned char j = i; j >= 1; j--)
        {
            printf("%4d ", pascal[j] += pascal[j - 1]);
        }

        printf("%4d \n", 1);
    }
}

ou, pour n'afficher qu'une ligne du triangle

void afficheTPascal(unsigned char rang)
{
    rang++;
    int pascal[rang];
    memset(pascal, 0, rang * sizeof(int));
    pascal[0] = 1;

    for (unsigned char i = 1; i < rang; i++)
    {
        for (unsigned char j = i; j >= 1; j--)
        {
            pascal[j] += pascal[j - 1];
        }
    }

    for (unsigned char i = 0; i < rang; i++)
    {
        printf("%4d ", pascal[i]);
    }

    putchar('\n');
}