Problem:
We say that a number is a palindrom if it is the sane when read from left to right or from right to left. For example, the number 75457 is a palindrom.
Of course, the property depends on the basis in which is number is represented. The number 17 is not a palindrom in base 10, but its representation in base 2 (10001) is a palindrom.
The objective of this problem is to verify if a set of given numbers are palindroms in any basis from 2 to 16.
Input Format:
Several integer numbers comprise the input. Each number 0 < n < 50000 is given in decimal basis in a separate line. The input ends with a zero.
Output Format:
Your program must print the message Number i is palindrom in basis where I is the given number, followed by the basis where the representation of the number is a palindrom. If the number is not a palindrom in any basis between 2 and 16, your program must print the message Number i is not palindrom.
Sample Input:
17 19 0
Sample Output:
Number 17 is palindrom in basis 2 4 16 Number 19 is not a palindrom
Solution:
// 声明:本代码仅供学习之用,请不要作为个人的成绩提交。 // http://blog.csdn.net/mskia // email: [email protected] #include <iostream> #include <vector> using namespace std;
int main( void ) { for ( ; ; ) { int number; cin >> number; if ( number == 0 ) { break; } vector< int > result; for ( int i = 2; i <= 16; ++i ) { vector< int > newnum;
int num = number; while ( num != 0 ) { newnum.push_back( num % i ); num /= i; }
int left = 0 , right = newnum.size( ) - 1; for ( ; left < right; ++left , --right ) { if ( newnum[ left ] != newnum[ right ] ) { goto NOT; } } result.push_back( i ); NOT:; } if ( result.size( ) > 0 ) { cout << "Number " << number << " is palindrom in basis "; vector< int >::iterator p = result.begin( ); cout << *p; ++p; for ( ; p != result.end( ); ++p ) { cout << " " << *p; } cout << endl; } else { cout << "Number " << number << " is not a palindrom" << endl; } result.clear( );
} return 0; }

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