day_1.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define ON 1
#define OFF 0

int main()
{
	FILE *fp;
	char *line = NULL;
	size_t len = 100;
	ssize_t read;
	int status = ON;
	int max_sum = 0;
	int partial_sum = 0;
	int num;

	fp = fopen("input.txt", "r");
	if (fp == NULL){
		exit(EXIT_FAILURE);
	}
	while ((read = getline(&line, &len, fp)) != -1) {
		if (strcmp(line, "\n") == 0){
			if (status == ON){
				status = OFF;
				if (partial_sum > max_sum){
					max_sum = partial_sum;
				}
			}
		} else {
			if (status == OFF){
				status = ON;
				partial_sum = 0;
			}
		}
		if (status == ON){
			num = atoi(line);
			partial_sum += num;
		}

	}
	printf("Solution: %d\n", max_sum);
	fclose(fp);
	if (line)
		free(line);
	exit(EXIT_SUCCESS);
}