advent2025

commit 96dd562b534a326824aa829de48c0a0bd90c68a9
parent efa5101ffd0cf13d5a86e6def1e16ca4adab1bd5
Author: bsandro <email@bsandro.tech>
Date:   Sat,  6 Dec 2025 08:39:46 +0200

day06 p1; p2 is not finished yet

Diffstat:
A
day06.c
 | 
85
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

1 file changed, 85 insertions(+), 0 deletions(-)
diff --git a/day06.c b/day06.c
@@ -0,0 +1,85 @@
+#include <stdio.h>
+#include <inttypes.h>
+#include "cputime.h"
+
+// tail -n1 inputs/day06.txt | sed 's/\s/\n/g'|sort|grep '+\|*'|wc -l
+#define W 1001
+#define H 5
+#define DIG 4
+
+typedef struct {
+    char symbols[DIG];
+    int len;
+} Number;
+
+int btoi(int buf[16], int bufl) {
+    int num = 0;
+    for (int i=0;i<bufl;++i) num = num*10+buf[i];
+    return num;
+}
+
+uint64_t part1(int numbers[H][W], int x, char c) {
+    uint64_t num = 0;
+    for (int dy=0;dy<H;++dy) {
+        if (numbers[dy][x]==0) continue;
+        if (c=='*') num = (num==0?1:num) * numbers[dy][x];
+        if (c=='+') num += numbers[dy][x];
+    }
+    return num;
+}
+
+void reverse(char symbols[DIG]) {
+    for (int i=0;i<DIG/2;++i) {
+        char t = symbols[i];
+        symbols[i] = symbols[DIG-i-1];
+        symbols[DIG-i-1] = t;
+    }
+}
+
+uint64_t part2(Number digits[H][W], int x, char c) {
+    uint64_t num = 0;
+    for (int y=0;y<H;++y) {
+        for (int d=0;d<DIG;++d) {
+            Number n = digits[y][x];
+            printf("%2c",n.symbols[d]>0?n.symbols[d]:'0');
+        }
+        printf("\n");
+    }
+    (void)c;
+    return num;
+}
+
+int main(void) {
+    int numbers[H][W] = {0};
+    Number digits[H][W] = {0};
+    int x = 0;
+    int y = 0;
+    int buf[8] = {0};
+    int bufl = 0;
+    uint64_t p1 = 0;
+    uint64_t p2 = 0;
+    for (int c=getchar();c!=EOF;c=getchar()) {
+        if (c>='0'&&c<='9') {
+            buf[bufl++] = c-'0';
+            digits[y][x].symbols[digits[y][x].len++]=c;
+        } else if (c==' '||c=='\n') {
+            if (bufl!=0) {
+                numbers[y][x] = btoi(buf, bufl);
+                reverse(digits[y][x].symbols);
+                bufl = 0;
+                x++;
+            }
+            if (c=='\n') {
+                y++;
+                x = 0;
+            }
+        } else if (c=='*'||c=='+') {
+            p1 += part1(numbers, x, c);
+            p2 += part2(digits, x, c);
+            x++;
+        }
+    }
+    printf("p1: %"PRIu64"\np2: %"PRIu64"\n", p1, p2);
+    return 0;
+}
+// 540238937 wrong