zoj1334Basically Speaking

ZOJ Problem Set - 1334
Basically Speaking
Time Limit: 2 Seconds      Memory Limit: 65536 KB
The Really Neato Calculator Company, Inc. has recently hired your team to help design their Super Neato Model I calculator. As a computer scientist you suggested to the company that it would be neato if this new calculator could convert among number bases. The company thought this was a stupendous idea and has asked your team to come up with the prototype program for doing base conversion. The project manager of the Super Neato Model I calculator has informed you that the calculator will have the following neato features:
It will have a 7-digit display.


Its buttons will include the capital letters A through F in addition to the digits 0 through 9.


It will support bases 2 through 16.




Input


The input for your prototype program will consist of one base conversion per line. There will be three numbers per line. The first number will be the number in the base you are converting from. The second number is the base you are converting from. The third number is the base you are converting to. There will be one or more blanks surrounding (on either side of) the numbers. There are several lines of input and your program should continue to read until the end of file is reached.




Output


The output will only be the converted number as it would appear on the display of the calculator. The number should be right justified in the 7-digit display. If the number is to large to appear on the display, then print ``ERROR'' (without the quotes) right justified in the display.


Sample Input




1111000 2 10
  1111000 2 16
2102101  3 10
2102101 3   15
12312 4   2
1A   15 2
   1234567 10 16
  ABCD 16 15


Sample Output


    120
     78
   1765
    7CA
  ERROR
  11001
 12D687

   D071

题意：就是将一个数从一个进制转换成另外一个进制，不是很难，注意右边对齐，超出7位就不显示了。

#include<stdio.h>#include<math.h>int main(){int from,to,i,sum,digit;char a[8];while(scanf("%s %d %d",&a,&from,&to)!=EOF){sum=0;digit=0;for(i=0;a[i]!='\0';i++);for(i--;i>=0;i--){if(a[i]>='0'&&a[i]<='9')    sum+=(a[i]-'0')*pow(from,digit);else sum+=(a[i]-55)*pow(from,digit);digit++;}i=0;while(sum&&i<8){digit=sum%to;sum=sum/to;if(0<=digit&&digit<=9)a[i]=digit+'0';else a[i]=digit+55;i++;}if(i==8)printf("  ERROR");else {i--;for(digit=7-i-2;digit>=0;digit--)printf(" ");for(;i>=0;i--)printf("%c",a[i]);}printf("\n");}return 0;}