optimise day four

diff --git a/14a.c b/14a.c
index 7b52084..10dea23 100644 (file)
--- a/14a.c
+++ b/14a.c
@@ -1,58 +1,63 @@
 #include <stdio.h>
 #include <stdbool.h>
 #include <limits.h>
+#include <string.h>
 
-#include <uthash.h>
+struct template { char x1; char x2; char ins; };
 
-struct pair { char x; char y; };
-struct template { struct pair key; char ins; UT_hash_handle hh; };
+#define lookup(i, x1, x2) (i)[((x1)-'A')+((x2)-'A')*26]
 
 int main()
 {
-       char *input = NULL, *buf = NULL, *oldinput = NULL;
-       size_t inputlen = 0, len;
-       struct template *template = NULL;
+       char *buf = NULL;
+       size_t len;
+       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, last = first;
+       unsigned long freq[26] = {0};
+       while ( (c = getchar()) != '\n') {
+               lookup(input, last, c) = 1;
+               last = c;
+       }
 
-       if (getline(&input, &inputlen, stdin) == -1)
-               return 1;
        while (getline(&buf, &len, stdin) != -1) {
-               if (strcmp(buf, "\n") == 0)
+               if (buf[0] == '\n')
                        continue;
-               struct template *t = calloc(1, sizeof(struct template));
-               t->key.x = buf[0];
-               t->key.y = buf[1];
-               t->ins = buf[6];
-               HASH_ADD(hh, template, key, sizeof(struct pair), t);
+               template[ntemplate++] = (struct template)
+                       {.x1=buf[0], .x2=buf[1], .ins=buf[6]};
        }
 
-       for (int i = 0; i<20; i++) {
-               free(oldinput);
-               oldinput = input;
-               input = malloc(inputlen *= 2);
-               inputlen = 0;
-               char *c;
-               for (c = &oldinput[0]; *c != '\0'; c++) {
-                       input[inputlen++] = *c;
-                       struct pair p = {.x=c[0], .y=c[1]};
-                       struct template *t;
-                       HASH_FIND(hh, template, &p, sizeof(struct pair), t);
-                       if (t)
-                               input[inputlen++] = t->ins;
+       for (int step = 0; step < 10; step++) {
+               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;
                }
-               input[inputlen++] = '\0';
+               unsigned long *t = newinput;
+               newinput = input;
+               input = t;
+               memset(&newinput[0], 0, sizeof(input1));
        }
 
-       int freq[255] = {0};
-       int mcommon = 0, lcommon = INT_MAX;
-       for (char *c = &input[0]; *c != '\0'; *c++) {
-               freq[*c]++;
+       for (char x = 'A'; x<='Z'; x++) {
+               for (char y = 'A'; y<='Z'; y++) {
+                       freq[x-'A'] += lookup(input, x, y);
+                       freq[y-'A'] += lookup(input, x, y);
+               }
        }
-       for (int i = 0; i<255; i++) {
-               if (freq[i] > mcommon)
-                       mcommon = freq[i];
-               if (freq[i] > 1 && freq[i] < lcommon)
-                       lcommon = freq[i];
+       freq[first-'A']++;
+       freq[last-'A']++;
+
+       unsigned long min = ULONG_MAX, max = 0;
+       for (int i = 0; i<26; i++) {
+               max = freq[i] > max ? freq[i] : max;
+               min = freq[i] > 1 && freq[i] < min ? freq[i] : min;
        }
 
-       printf("%d\n", mcommon-lcommon);
+       printf("%lu\n", max/2-min/2);
 }

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++) {

diff --git a/Makefile b/Makefile
index 50c1a9f..64234e9 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 CFLAGS:=-Wall -Wextra -O3
 LFLAGS:=-f
 
-BINARIES:=$(foreach num,$(shell seq -f '%02.0f' 1 11),$(num)a $(num)b)
+BINARIES:=$(foreach num,$(shell seq -f '%02.0f' 1 14),$(num)a $(num)b)
 
 all: $(BINARIES)