poj 1047 Round and Round We Go

poj 1047 Round and Round We Go

#include<stdio.h>#include<string.h> char *strrev( char *s ){if( s == NULL || s[ 0 ] == '' )return s;for( char t, *p = s, *q = s + strlen( s ) - 1; p < q; p++, q-- )t = *p, *p = *q, *q = t;return s;}int main(){char input[ 65 ];char c1[ 65 ], c2[ 130 ];int length;int i, j, k, p, q;int flag;while( memset( input, 0, sizeof( input ) ) && scanf( "%s", input ) != EOF ){length = strlen( input );memset( c1, 0, sizeof( c1 ) );strncpy( c1, input, length );//复制到c1 strrev( c1 ); //倒置 // 用来判断循环数，例如 142857 ，c2 就为 142857142857，结果只要是 c2 的子串，就是循环的memset( c2, 0, sizeof( c2 ) );strncpy( c2, c1, length ); strncpy( c2 + length, c1, length );flag = 1;for( i = 2; i <= length; i++ ){for( j = 0; j < length; j++ ){c1[ j ] += ( c2[ j ] - '0' );if( c1[ j ] > '9' ){c1[ j ] -= 10;++ c1[ j + 1 ];}}if( strlen( c1 ) > length ){flag = 0;break;}if( !strstr( c2, c1 ) ){flag = 0;break;}}if( flag )printf( "%s is cyclicn", input );elseprintf( "%s is not cyclicn", input );}return 0;}