1148: Basic

题目描述

The programming language Ada has integer constants that look like this: 123, 8#123#, 16#abc#. These constants represent the integers 123, 83 (123 base 8) and 2739 (abc base 16). More precisely, an integer may be a decimal integer given as a sequence of one or more digits less than 10, or it may be an integer to some specific base, given as the base followed by a sequence of one or more digits less than the base enclosed by # symbols. Lower case letters from a through f are used as the digits representing 10 through 15. In Ada, the base, if specified, must be a sequence of decimal digits. For this problem, however, the base may be of any form described above so long as it represents an integer between 2 and 16 inclusive.
The first line of input contains a positive integer n. n lines follow. For each line of input, output a line "yes" if it is a valid integer constant according to the above rules; otherwise output a line containing "no". Input lines contain no spaces and are between 1 and 80 characters in length.

输入

暂无

输出

暂无

样例输入

5
2#101#
2#101##123#
17#abc#
16#123456789abcdef#
16#123456789abcdef#123456789abcdef#

样例输出

yes
yes
no
yes
no

参考代码

#include <stdio.h>
int i,j,k,m,n;
char buf[1000];
int state;
double base, val;
int v[256];
#define check(x) if (!(x)) 
{
    printf("non");goto bad;}
#define DSTART 1
#define DEC 2
#define BSTART 3
#define BASE 4
#define BDONE 5
main(){
   for (i=0;i<255;i++) v[i] = -1;
   for (i=0;i<=9;i++) v[i+'0'] = i;
   for (i=0;i<=5;i++) v[i+'a'] = i+10;
   scanf("%d",&n);
   gets(buf);
   while (n--) {
      if (!gets(buf)) {
         printf("Error - short input!n"); 
         exit(1);
      }
      state = DSTART;
      val = base = 0;
      for (i=0;buf[i];i++) {
         char c = buf[i];
         switch(state) {
            case DSTART: {
               check(v[c] >=0 && v[c] <= 9);
               val = v[c];
               state = DEC;
               break;
            }
            case DEC: {
               if (c == '#') {
                  check(val >= 2 && val <= 16);
                  base = val;
                  val = 0;
                  state = BSTART;
                  break;
               }
               check (v[c] >= 0 && v[c] <= 9);
               val = val * 10 + v[c];
               break;
            }
            case BSTART: {
               check (v[c] >= 0 && v[c] < base);
               val = v[c];
               state = BASE;
               break;
            }
            case BASE: {
               if (c == '#') {
                  state = BDONE;
                  break;
               }
               check (v[c] >= 0 && v[c] < base);
               val = val * base + v[c];
               break;
           }
           case BDONE: {
              check (c == '#');
              check (val >=2 && val <= 16);
              base = val;
              val = 0;
              state = BSTART;
              break;
           }
        }
      }
      check(state == DEC || state == BDONE);
      printf("yesn");
      bad:;
   }
   if (gets(buf)) printf("Error - excessinput!n");
}

解析

暂无