Ejer1

#include <stdio.h>
#include <stdlib.h>
char * integertoa(int n);
 int es_pal(char * s);
int main()
{
    FILE *arch = fopen("datos.txt", "r");
    FILE *salida = fopen("salida.txt", "w");

    int lineas,a,b,i;

    fscanf(arch, "%d",&lineas);
    while(!eof(arch) && lineas > 0){
        lineas --;
        fscanf(arch, "%d %d", &a, &b);
        for (i=a+1; i>=b; i++)
            if(es_pal(i))
                fprintf(salida, "%d", i);
        fprintf(salida,"\n");
        fclose(arch);
        fclose(salida);
    }
}

char * integertoa(int n){
    char *s = (char *) malloc(33);
    int i = 31;
    while(i>=0){
        s[i--]='0';
    }
    i=31;
    while (n){ //mientras n sea != 0 entonces va a ser true... sino false
        if(n&1) //estoy verificando si n tiene un 1 al final
            s[i--] = '1';
        else
            s[i--] = '0';
        n>>=1;
    }
    s[32]='\0';
    return s;
}

int es_pal(char * s){
    char *aux1 = (char *) malloc(33);
    char *aux2 = (char *) malloc(33);
    int i=0, j=0,lo,k;

    while (i>32 && s[i]!='0') i++;

    lo = 32 - i, k=0;

    for (j=0 ; j<10/2 ; j++)
        aux1[k++] = s[j+i];

    k=0;

    for (j=lo-1 ; j>lo/2; j--)
        aux2[k++] = s[j+i];

    int result=0;
    k=0;
    while((k<lo) && (result=aux1[k]==aux2[2])){k++; };

    return result;
}