10b.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3
   4 char cmap[] = { [')']='(', [']']='[', ['}']='{', ['>']='<' };
   5 long rmap[] = { ['(']=1, ['[']=2, ['{']=3, ['<']=4 };
   6
   7 void parse_line(const char *buf, long scores[], int *nscores)
   8 {
   9         char stack[200] = {0};
  10         int sp = 0;
  11         long score = 0;
  12         for (const char *p = buf; ; p++) {
  13                 switch (*p) {
  14                 case '(':
  15                 case '[':
  16                 case '{':
  17                 case '<':
  18                         stack[sp++] = *p;
  19                         break;
  20                 case ')':
  21                 case ']':
  22                 case '}':
  23                 case '>':
  24                         //corrupt
  25                         if (stack[--sp] != cmap[(int)*p])
  26                                 return;
  27                         stack[sp] = '\0';
  28                         break;
  29                 case '\0':
  30                 case '\n':
  31                         score = 0;
  32                         while (sp>0)
  33                                 score = score*5 + rmap[(int)stack[--sp]];
  34                         scores[(*nscores)++] = score;
  35                         return;
  36                 }
  37         }
  38 }
  39
  40 int longcmp(const void *l, const void *r)
  41 {
  42         return *(const long *)l-*(const long *)r < 0 ? -1 : 1;
  43 }
  44
  45 int main()
  46 {
  47         char *buf = NULL;
  48         size_t len = 0;
  49         long scores[100] = {0};
  50         int nscores = 0;
  51         while (getline(&buf, &len, stdin) != -1)
  52                 parse_line(buf, scores, &nscores);
  53         qsort(scores, nscores, sizeof(long), &longcmp);
  54         printf("%ld\n", scores[nscores/2]);
  55 }