advent2025

commit 186d00385ac90e6275a6d1df0b033c42000fe2fa
parent 6a2844416f21d4c56259a9a6550d05bd883bc4b8
Author: bsandro <email@bsandro.tech>
Date:   Sat, 13 Dec 2025 23:34:10 +0200

day10 cleanup

Diffstat:
M
day10.c
 | 
78
+++++++++++++++++++++++-------------------------------------------------------

1 file changed, 23 insertions(+), 55 deletions(-)
diff --git a/day10.c b/day10.c
@@ -7,6 +7,7 @@
 #include "cputime.h"
 
 #define BUF_SIZE 256
+#define MAX_TRIES 20
 
 static int btoi(int bufl, char buf[bufl]) {
     int num = 0;
@@ -15,70 +16,37 @@ static int btoi(int bufl, char buf[bufl]) {
 }
 
 typedef struct {
-    int toggles_l;
-    int toggles[16];
-} Button;
-
-typedef struct {
-    int lights_l;
-    bool lights[16];
     uint16_t indicators;
     int buttons_l;
-    Button buttons[16];
-    int buttons1_l;
-    uint16_t buttons1[16];
+    uint16_t buttons[16];
     int joltages_l;
-    int joltages[16]; // same number as lights
+    int joltages[16];
 } Machine;
 
-static void m_lights_add(Machine *m, int bufl, char buf[bufl]) {
-    for (int i=0;i<bufl;++i) {
-        m->lights[m->lights_l++] = buf[i]=='#';
-    }
-}
-
 static void m_indicators_add(Machine *m, int bufl, char buf[bufl]) {
-    for (int i=0;i<bufl;++i) {
-        if (buf[i]=='#') m->indicators |= 1<<i;
-    }
+    for (int i=0;i<bufl;++i)
+        if (buf[i]=='#')
+            m->indicators |= 1<<i;
 }
 
-static void m_button_add(Machine *m, int bufl, char buf[bufl]) {
-    Button *btn = &m->buttons[m->buttons_l++];
-    for (int i=0;i<bufl;++i) {
-        btn->toggles[btn->toggles_l++] = buf[i]-'0';
-    }
-}
-
-static void m_button1_add(Machine *m, int bufl, char buf[bufl]) {
-    int b = m->buttons1_l++;
-    for (int i=0;i<bufl;++i) {
-        m->buttons1[b] |= 1<<(buf[i]-'0');
-    }
+static void m_buttons_add(Machine *m, int bufl, char buf[bufl]) {
+    int b = m->buttons_l++;
+    for (int i=0;i<bufl;++i)
+        m->buttons[b] |= 1<<(buf[i]-'0');
 }
 
 static void m_joltage_add(Machine *m, int jolt) {
     m->joltages[m->joltages_l++] = jolt;
 }
 
-// used in p2
-static bool btn_lights(Button *btn, int light) {
-    for (int i=0;i<btn->toggles_l;++i) {
-        if (btn->toggles[i]==light) {
-            return true;
-        }
-    }
-    return false;
-}
-
 static bool try_combination(Machine *m, int comb_l, uint16_t comb[comb_l], int p) {
     if (p==comb_l) {
         uint16_t c = 0;
         for (int i=0;i<comb_l;++i) c ^= comb[i];
         return m->indicators==c;
     }
-    for (int i=0;i<m->buttons1_l;++i) {
-        uint16_t btn = m->buttons1[i];
+    for (int i=0;i<m->buttons_l;++i) {
+        uint16_t btn = m->buttons[i];
         if (p>0&&comb[p-1]==btn) continue; // do not press same button twice in a row
         comb[p] = btn;
         if (try_combination(m, comb_l, comb, p+1)) return true;
@@ -89,11 +57,11 @@ static bool try_combination(Machine *m, int comb_l, uint16_t comb[comb_l], int p
 static int64_t solve_glpk(Machine *m) {
     int btnl = m->buttons_l;
     int cntl = m->joltages_l;
-    // matrix of buttons/counters
-    int matbc[btnl][cntl];
+    int matbc[btnl][cntl]; // matrix of buttons/counters
     for (int b=0;b<btnl;++b) {
         for (int c=0;c<cntl;++c) {
-            matbc[b][c] = btn_lights(&m->buttons[b], c) ? 1 : 0;
+            uint16_t i = 1<<c;
+            matbc[b][c] = (m->buttons[b]&i)==0 ? 0 : 1;
         }
     }
 
@@ -141,22 +109,22 @@ int main(void) {
     bool parse_joltages = false;
     for (int c=getchar();c!=EOF;c=getchar()) {
         if (c==']') {
-            m_lights_add(&machines[machines_l], bufl, buf);
             m_indicators_add(&machines[machines_l], bufl, buf);
             bufl = 0;
         }
         else if (c==')') {
-            m_button_add(&machines[machines_l], bufl, buf);
-            m_button1_add(&machines[machines_l], bufl, buf);
+            m_buttons_add(&machines[machines_l], bufl, buf);
             bufl = 0;
         }
-        else if ((c>='0'&&c<='9')||c=='.'||c=='#') buf[bufl++] = c;
-        else if (c=='\n') {
+        else if ((c>='0'&&c<='9')||c=='.'||c=='#') {
+            buf[bufl++] = c;
+        } else if (c=='\n') {
             machines_l++;
             bufl = 0;
             parse_joltages = false;
-        } else if (c=='{') parse_joltages = true;
-        else if (parse_joltages&&(c==','||c=='}')) {
+        } else if (c=='{') {
+            parse_joltages = true;
+        } else if (parse_joltages&&(c==','||c=='}')) {
             int jolt = btoi(bufl, buf);
             m_joltage_add(&machines[machines_l], jolt);
             bufl = 0;
@@ -165,7 +133,7 @@ int main(void) {
     int64_t part1 = 0;
     int64_t part2 = 0;
     for (int i=0;i<machines_l;++i) {
-        for (int j=1;j<=20;++j) {
+        for (int j=1;j<=MAX_TRIES;++j) {
             uint16_t comb[j];
             if (try_combination(&machines[i], j, comb, 0)) {
                 part1 += j;