Ejemplo026.c

Go to the documentation of this file.

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <math.h>
 
#define BIT(n)              (1<<(n))
#define BIT_GET(x,n)        ((x) & BIT(n))
#define BIT_SET(x,n)        ((x) |= BIT(n))
#define BIT_CLEAR(x,n)      ((x) &= ~BIT(n))
#define BIT_TOGGLE(x,n)     ((x) ^= BIT(n))
#define BIT_WRITE(x,n,v)    ((v)?BIT_SET(x,n):BIT_CLEAR(x,n))
#define ES_PAR(x)           (!BIT_GET(x,0))
#define N                   50
 
int main(int argc, char *argv[])
{
    char str[N], strP[N], strR[N], c, p, v;
    int i, j, k, l, nc, cc, cb, np, p2, p2f, cc2, cb2;
    srand(time(NULL));
    i = 0;
    do{
        c = getchar();
        str[i] = c;
        i++;
    }while(c!=10&&i<(N-1));
    nc = i-1;
    str[nc] = '\0';
    np = (int)(log2(nc+log2(nc)+1)+1);
    printf("NP = %d\n", np);
    printf("%s (%d, %d)\n", str, nc, np);
    for(i=0, j=0, p2=1; i<(nc+np); i++)
    {
        if((i+1)==p2)
        {
            strP[i] = 0;
            p2<<=1;
        }
        else
        {
            c = str[j++];
            strP[i] = c;
            for(k=0, p2f=1; k<np; k++)
            {
                if(p2f&(i+1))
                    strP[p2f-1]^=c;
                p2f<<=1;
            }
        }
    }
    strP[nc+np] = '\0';
    cc = rand()%(nc+np);
    cb = rand()%8;
    BIT_TOGGLE(strP[cc],cb);
    printf("%s\n", strP);
    for(i=0, j=0, l=0, p2=1; i<(nc+np); i++)
    {
        if((i+1)==p2)
        {
            strR[nc+1+l] = strP[i];
            l++;
            p2 <<= 1;
        }
        else
        {
            c = strP[i];
            strR[j++] = c;
            for(k=0, p2f=1; k<np; k++)
            {
                if(p2f&(i+1))
                    strR[nc+1+k]^=c;
                p2f<<=1;
            }
        }
    }
    strR[nc] = '\0';
    strR[nc+np+1] = '\0';
    printf("%s (%d, %d)\n", strR, cc, cb);
    for(i=0, cc2=0; i<np; i++)
    {
        printf("%d\t", strR[nc+1+i]);
        BIT_WRITE(cc2,i,strR[nc+1+i]);
        if(strR[nc+1+i])
            cb2 = log2(strR[nc+1+i]);
    }
    printf("(%d, %d)\n", cc2-1, cb2);
    BIT_TOGGLE(strP[cc2-1],cb2);
    printf("%s\n", strP);
    return 0;
}