usaco Palindromic Squares

 

Palindromic Squares

回文平方数
Rob Kolstad

译 by !Starliu

回文数是指从左向右念和从右像做念都一样的数。如12321就是一个典型的回文数。

给定一个进制B(2<=B<=20十进制)，输出所有的大于等于1小于等于300且它的平方用B进制表示时是回文数的数。用’A’,’B’……表示10，11等等。

PROGRAM NAME: palsquare

INPUT FORMAT

共一行，一个单独的整数B(B用十进制表示)。

SAMPLE INPUT (file palsquare.in)

10

OUTPUT FORMAT

每行两个数字，第二个数是第一个数的平方，且第二个数是回文数。(注意:这两个数都应该在B那个进制下)

SAMPLE OUTPUT (file palsquare.out)

1 1

2 4

3 9

11 121

22 484

26 676

101 10201

111 12321

121 14641

202 40804

212 44944

264 69696

代码：

#include <iostream>#include <cstdio>#include <cstring>using namespace std;FILE *fin = fopen("palsquare.in","r");FILE *fout = fopen("palsquare.out","w");int b;char sq[10];void my_sqrt(int k){int i,t = k*k,c=0;char tmp;int tm;while(t){tm = t%b;if(tm >=10)tmp = 'A'+tm-10;elsetmp = tm + '0';sq[c++] = tmp;t /= b;}for(i=0; i<c/2; i++)if(sq[i] != sq[c-i-1])break;if(i>=c/2){char sqr[10];int cc = 0;while(k){tm = k%b;if(tm >=10)tmp = 'A'+tm-10;elsetmp = tm + '0';sqr[cc++] = tmp;k /= b;}for(i=cc-1; i>=0; i--)fprintf(fout,"%c",sqr[i]);fprintf(fout," ");for(i=c-1; i>=0; i--)fprintf(fout,"%c",sq[i]);fprintf(fout,"/n");}}int main(void){int i;fscanf(fin,"%d",&b);for(i=1; i<=300; i++)my_sqrt(i);return 0;}