commit 5119833f6a8e73d814353d5314346fcbd8d54299
parent 6f21b3ca67bc035c2cc828736363abb9787b6bfa
Author: thing1 <thing1@seacrossedlovers.xyz>
Date: Thu, 4 Dec 2025 15:57:41 +0000
day 3 done finally
Diffstat:
| M | 3/3b.c | | | 71 | +++++++++++++++++++++++++++++++++++++---------------------------------- |
1 file changed, 37 insertions(+), 34 deletions(-)
diff --git a/3/3b.c b/3/3b.c
@@ -2,61 +2,64 @@
#include <stdlib.h>
#include <string.h>
-/* TODO
-make it so i have an array of pointers of all the high values, then i sort that array
+/* method
+
+we know we need 12 bats, so to find the largest number,
+we can find the largest digit for each, position. To do this
+we can find the difference in length of the input and 12,
+then from the first n (the difference in length) digits, pick
+the highest one. Then repeat the function for the other
+digits, using the previously chosen digit as an input and
+subtracting 1 from the length
*/
char *
-findhighest(char *s, char **exclude) {
- char z = 0;
- char *highest = &z;
-
- for (char *c = s; *c != '\n' && *c != 0; c++) {
- for (int i = 0; i <12; i++)
- if (exclude[i] == c) goto again;
-
- if (*c > *highest)
- highest = c;
-again:
+findhighest(char *start, char *end) {
+ char *highest = start++;
+ while (start != end) {
+ if (*start > *highest)
+ highest = start;
+ start++;
}
return highest;
}
-int
-sort(const void *a, const void *b) {
- char *s1 = *(char **)a, *s2 = *(char **)b;
- return (s1 < s2);
-}
-
char *
-highestdigits(char *s) {
- static char high[12] = {0};
- char *highest[12] = {0};
+finddigit(char *in, int len) {
+ int off;
+ char *digit;
- for (int i = 0; i < 12; i++) {
- highest[i] = findhighest(s, highest);
- }
+ off = strlen(in) - len;
+ digit = findhighest(in, in + off + 1);
- qsort(highest, 12, sizeof(char *), &sort);
+ return digit;
+}
- for (int i = 0; i < 12; i++)
- high[i] = *highest[i];
+char **
+finddigits(char *in) {
+ static char *digits[12];
- return high;
-}
+ for (int len = 12; len >= 0; len--) {
+ digits[12 - len] = finddigit(in, len);
+ in = digits[12 - len] + 1;
+ }
+ return digits;
+}
int
main() {
long long int total = 0;
- char *digits, num[13] = {0}, line[256];
+ char **digits, num[13] = {0};
+ char line[256] = {0};
while (fgets(line, 256, stdin)) {
- digits = highestdigits(line);
- memcpy(num, digits, 12);
+ line[strlen(line) - 1] = 0;
+ digits = finddigits(line);
+ for (int i = 0; i < 12; i++)
+ num[i] = *digits[i];
printf("%s\n", num);
total += atoll(num);
}
-
printf("%lld\n", total);
}
\ No newline at end of file
