81 lines
1.9 KiB
C
81 lines
1.9 KiB
C
#include <stdio.h>
|
|
#include <string.h>
|
|
#include <limits.h>
|
|
|
|
char *firstMatch (char *string, int offset, int *digit);
|
|
char *lastMatch (char *string, int *digit);
|
|
|
|
// array of strings with all digits and human-numbers
|
|
const char *numbers[] = {"one", "two", "three", "four", "five", "six",
|
|
"seven", "eight", "nine",
|
|
"0", "1", "2", "3", "4", "5", "6", "7", "8", "9"};
|
|
|
|
int main()
|
|
{
|
|
FILE *input;
|
|
input = fopen("./input", "r");
|
|
|
|
int digit = 0;
|
|
int value = 0;
|
|
int sum = 0;
|
|
char row[100];
|
|
|
|
// use fgets
|
|
while ((fgets(row, 100, input)) != 0) {
|
|
firstMatch(row, 0, &digit);
|
|
value = digit * 10;
|
|
|
|
lastMatch(row, &digit);
|
|
value += digit;
|
|
|
|
printf("value: %d\n", value);
|
|
sum += value;
|
|
}
|
|
|
|
fclose(input);
|
|
printf("%u\n", sum);
|
|
}
|
|
|
|
// function with input offset and string, returns offset (and val?)
|
|
// looks for every string / char, return lowest offset
|
|
// to find rightmost, repeatedly call this function with offset + 1
|
|
char *firstMatch (char *string, int offset, int *digit)
|
|
{
|
|
// this ptr is 1 step outside of the array, because the
|
|
// relational operators in C are only defined if both pointers
|
|
// point within the same array or one step beyond the last member
|
|
char *first = &string[99] + 1;
|
|
|
|
// looks for each number string from numbers[]
|
|
// and remembers the lowest pointer
|
|
char *match;
|
|
for (int i = 0; i < sizeof(numbers) / 8; i++) {
|
|
match = strstr(string + offset, numbers[i]);
|
|
if (match == 0) continue;
|
|
if (match < first) {
|
|
first = match;
|
|
if (i <= 8) {
|
|
*digit = i + 1;
|
|
} else {
|
|
*digit = i - 9;
|
|
}
|
|
}
|
|
}
|
|
|
|
// Pointer unchanged? No match, return NULL
|
|
if (first == &string[99] + 1) first = NULL;
|
|
return first;
|
|
}
|
|
|
|
char *lastMatch (char *string, int *digit)
|
|
{
|
|
char *last = &string[0];
|
|
int offset = 0;
|
|
while (firstMatch(string, offset, digit) >= last) {
|
|
if (firstMatch(string, offset, digit) == NULL) break;
|
|
last = firstMatch(string, offset, digit);
|
|
offset++;
|
|
}
|
|
return last;
|
|
}
|