cleanup

[advent21.git] / 14b.c

diff --git a/14b.c b/14b.c
index 83ebab0..2b505fa 100644 (file)
--- a/14b.c
+++ b/14b.c
@@ -3,42 +3,40 @@
 #include <limits.h>
 #include <string.h>
 
+struct template { char x1; char x2; char ins; };
+
 #define lookup(i, x1, x2) (i)[((x1)-'A')+((x2)-'A')*26]
 
 int main()
 {
        char *buf = NULL;
        size_t len;
-       char template[26*26] = {0};
-       unsigned long input1[26*26] = {0};
-       unsigned long input2[26*26] = {0};
-       unsigned long *input = input1;
-       unsigned long *newinput = input2;
+       int ntemplate = 0;
+       struct template template[100];
+       unsigned long input1[26*26] = {0}, input2[26*26] = {0};
+       unsigned long *input = input1, *newinput = input2;
 
        int first = getchar();
-       int c, oldc = first;
+       int c, last = first;
        unsigned long freq[26] = {0};
        while ( (c = getchar()) != '\n') {
-               lookup(input, oldc, c) = 1;
-               oldc = c;
+               lookup(input, last, c) = 1;
+               last = c;
        }
 
        while (getline(&buf, &len, stdin) != -1) {
                if (buf[0] == '\n')
                        continue;
-               lookup(template, buf[0], buf[1]) = buf[6];
+               template[ntemplate++] = (struct template)
+                       {.x1=buf[0], .x2=buf[1], .ins=buf[6]};
        }
 
        for (int step = 0; step < 40; step++) {
-               for (char x = 'A'; x<='Z'; x++) {
-                       for (char y = 'A'; y<='Z'; y++) {
-                               char ins = lookup(template, x, y);
-                               if (ins != '\0') {
-                                       unsigned long freq = lookup(input, x, y);
-                                       lookup(newinput, x, ins) += freq;
-                                       lookup(newinput, ins, y) += freq;
-                               }
-                       }
+               for (int i = 0; i<ntemplate; i++) {
+                       struct template t = template[i];
+                       unsigned long freq = lookup(input, t.x1, t.x2);
+                       lookup(newinput, t.x1, t.ins) += freq;
+                       lookup(newinput, t.ins, t.x2) += freq;
                }
                unsigned long *t = newinput;
                newinput = input;
@@ -53,7 +51,7 @@ int main()
                }
        }
        freq[first-'A']++;
-       freq[oldc-'A']++;
+       freq[last-'A']++;
 
        unsigned long min = ULONG_MAX, max = 0;
        for (int i = 0; i<26; i++) {