pat1019-简单模拟题
1019. General Palindromic Number (20)
A number that will be the same when it is written forwards or backwards is known as a Palindromic Number. For example, 1234321 is a palindromic number. All single digit numbers are palindromic numbers.
Although palindromic numbers are most often considered in the decimal system, the concept of palindromicity can be applied to the natural numbers in any numeral system. Consider a number N > 0 in base b >= 2, where it is written in standard notation with k+1 digits ai as the sum of (aibi) for i from 0 to k. Here, as usual, 0 <= ai < b for all i and ak is non-zero. Then N is palindromic if and only if ai = ak-i for all i. Zero is written 0 in any base and is also palindromic by definition.
Given any non-negative decimal integer N and a base b, you are supposed to tell if N is a palindromic number in base b.
Input Specification:
Each input file contains one test case. Each case consists of two non-negative numbers N and b, where 0 <= N <= 109 is the decimal number and 2 <= b <= 109 is the base. The numbers are separated by a space.
Output Specification:
For each test case, first print in one line "Yes" if N is a palindromic number in base b, or "No" if not. Then in the next line, print N as the number in base b in the form "ak ak-1 ... a0". Notice that there must be no extra space at the end of output.
Sample Input 1:27 2Sample Output 1:
Yes 1 1 0 1 1Sample Input 2:
121 5Sample Output 2:
No 4 4 1
源程序:
#include<iostream> using namespace std; int main(){ int N,base,Bsize=0; int buf[1002]; //数组内容未初始化 cin>>N>>base; if((N>=0)&&(base>=2)){ //注意值的取值边界,不要漏取。此处忽略了N取0的情况,导致一个测试case不过 while(N!=0){ buf[Bsize++]= N % base; //注意数组成员数量变量Bsize的值的变化,最后一次运算后,其值会+1 N=N/base; } bool flag=true; for(int i=0,j=Bsize-1;i<=j;i++,j--){ if(buf[i]!=buf[j]){ flag=false; break; } } if(flag){ cout<<"Yes"<<endl; }else{ cout<<"No"<<endl; } for(int j=Bsize-1;j>0;j--) cout<<buf[j]<<" "; //关于首尾部位的格式控制 cout<<buf[0]; } return 0; }