14a.c

   1 #include <stdio.h>
   2 #include <stdbool.h>
   3 #include <limits.h>
   4
   5 #include <uthash.h>
   6
   7 struct pair { char x; char y; };
   8 struct template { struct pair key; char ins; UT_hash_handle hh; };
   9
  10 int main()
  11 {
  12         char *input = NULL, *buf = NULL, *oldinput = NULL;
  13         size_t inputlen = 0, len;
  14         struct template *template = NULL;
  15
  16         if (getline(&input, &inputlen, stdin) == -1)
  17                 return 1;
  18         while (getline(&buf, &len, stdin) != -1) {
  19                 if (strcmp(buf, "\n") == 0)
  20                         continue;
  21                 struct template *t = calloc(1, sizeof(struct template));
  22                 t->key.x = buf[0];
  23                 t->key.y = buf[1];
  24                 t->ins = buf[6];
  25                 HASH_ADD(hh, template, key, sizeof(struct pair), t);
  26         }
  27
  28         for (int i = 0; i<20; i++) {
  29                 free(oldinput);
  30                 oldinput = input;
  31                 input = malloc(inputlen *= 2);
  32                 inputlen = 0;
  33                 char *c;
  34                 for (c = &oldinput[0]; *c != '\0'; c++) {
  35                         input[inputlen++] = *c;
  36                         struct pair p = {.x=c[0], .y=c[1]};
  37                         struct template *t;
  38                         HASH_FIND(hh, template, &p, sizeof(struct pair), t);
  39                         if (t)
  40                                 input[inputlen++] = t->ins;
  41                 }
  42                 input[inputlen++] = '\0';
  43         }
  44
  45         int freq[255] = {0};
  46         int mcommon = 0, lcommon = INT_MAX;
  47         for (char *c = &input[0]; *c != '\0'; *c++) {
  48                 freq[*c]++;
  49         }
  50         for (int i = 0; i<255; i++) {
  51                 if (freq[i] > mcommon)
  52                         mcommon = freq[i];
  53                 if (freq[i] > 1 && freq[i] < lcommon)
  54                         lcommon = freq[i];
  55         }
  56
  57         printf("%d\n", mcommon-lcommon);
  58 }