aoc

Advent of Code challenges
log files refs
aoc_2023_1_1.c (1036B)
      1#include <stdio.h>
      2#include <stdlib.h>
      3#include <string.h>
      4#include <ctype.h>
      5
      6#define MAX_DIGITS 100
      7
      8typedef struct {
      9  int count;
     10  char digits[MAX_DIGITS];
     11} line_t;
     12
     13long perform(char *data) {
     14  (void) data;
     15  int len = strlen(data);
     16  int size = 0;
     17  for (int i = 0; i < len; i++) {
     18    char c = data[i];
     19    if (c == '\n') {
     20      size++;
     21    }
     22  }
     23  int idx = 0;
     24  line_t lines[size];
     25  lines[idx] = (line_t) { 0, {0} };
     26  for (int i = 0; i < len; i++) {
     27    char c = data[i];
     28    if (isdigit(c)) {
     29      line_t *line = &lines[idx];
     30      line->digits[line->count++] = c;
     31    }
     32    if (c == '\n') {
     33      idx++;
     34      lines[idx] = (line_t) { 0, {0} };
     35    }
     36  }
     37  int sum = 0;
     38  for (int i = 0; i < idx; i++) {
     39    line_t *line = &lines[i];
     40    if (line->count == 0) {
     41      continue;
     42    }
     43    char set = line->digits[0];
     44    char end = set;
     45    if (line->count > 1) {
     46      end = line->digits[line->count - 1];
     47    }
     48    char str[2] = { set, end };
     49    int digit = strtol(str, NULL, 10);
     50    sum += digit;
     51  }
     52  return sum;
     53}