Pro81:Palindromic Square

Palindromes are numbers that read the same forwards as backwards. The number 12321 is a typical palindrome. </p>

Given a number base B (2 <= B <= 20 base 10), print all the integers N (1 <= N <= 300 base 10) such that the square of N is palindromic when expressed in base B; also print the value of that palindromic square. Use the letters 'A', 'B', and so on to represent the digits 10, 11, and so on. </p>

Print both the number and its square in base B. </p>

PROGRAM NAME: palsquare</h3>

INPUT FORMAT</h3> A single line with B, the base (specified in base 10).

SAMPLE INPUT (file palsquare.in) </h3>

10 </pre>

OUTPUT FORMAT</h3>  Lines with two integers represented in base B.  The first integer is the number whose square is palindromic; the second integer is the square itself.

SAMPLE OUTPUT (file palsquare.out)</h3>
1 1 2 4 3 9 11 121 22 484 26 676 101 10201 111 12321 121 14641 202 40804 212 44944 264 69696 

/*
ID: hippo he
LANG: C
TASK: palsquare
*/
#include
#include
char pals[50][20];
const char scale[]="0123456789ABCDEFGHIJK";
char nin[10];
void input(int *base)
{
    FILE *fp=fopen("palsquare.in","r");
    fscanf(fp,"%d",base);
}
void transform(int n,int R,char **end)
{
    memset(nin,'0',sizeof(nin));
    int i=0;
    while(n)
    {
        nin[i]=scale[n%R];
        n/=R;
        i++;
    }
    nin[i]=0;
    *end=&nin[i-1];
}
int ispal(char* nin,char *end)
{
    char* p=nin,*q=end;
    while(p    {
        if(*q!=*p)return 0;
        q--;
        p++;
    }
    return 1;
}
void output(int n)
{
    int i;
    char *p,*q,tmp;
    FILE *fp=fopen("palsquare.out","w");
    for(i=0;i    {
        p=pals[i];
        for(q=p;*q;q++);q--;
        while(q>p)
        {
            tmp=*p;
            *p=*q;
            *q=tmp;
            p++;q--;
        }
        fprintf(fp,"%s %sn",pals[i],pals[i+1]);
    }
}
int main (int argc, char const* argv[]) {
    int n=0,base,i,R;
    char *end1=NULL;
    char *end2=NULL;
    input(&base);
    for(i=1;i<=300;i++)
    {
            transform(i*i,base,&end2);
            if(ispal(nin,end2))
            {
                transform(i,base,&end1);
                strcpy(pals[n++],nin);
                transform(i*i,base,&end2);
                strcpy(pals[n++],nin);
            }
    }
    output(n-1);
    return 0;
}
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