3 files changed, 117 insertions(+), 0 deletions(-)

M README.md
A main1.c
A main2.c

@@ 3,3 3,6 @@
 Each day is tagged with a git tag.
 
 Compile the code with `cc main.c` and run with `./a.out`.
+
+Some days may have multiple challenges, the first would be in `main1.c`, the
+second in `main2.c` and so on.

@@ 0,0 1,46 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+FILE *
+openInputFile(void)
+{
+	FILE *fp = fopen("input.txt","r");
+	if (fp == NULL)
+	{
+		printf("Could not open file: input.txt\n");
+		exit(EXIT_FAILURE);
+	}
+	return fp;
+}
+
+int
+main(void)
+{
+	char *line = NULL;
+	int increases = 0;
+	int currentValue = 0;
+	int previousValue = -1;
+	size_t len = 0;
+	ssize_t read;
+
+	FILE *fp = openInputFile();
+
+	while ((read = getline(&line, &len, fp)) != -1)
+	{
+		if (previousValue < 0)
+			previousValue = atoi(line);
+
+		currentValue = atoi(line);
+
+		if (currentValue > previousValue)
+			increases++;
+
+		previousValue = currentValue;
+	}
+
+	fclose(fp);
+	if (line)
+		free(line);
+	printf("%d\n", increases);
+	exit(EXIT_SUCCESS);
+}

@@ 0,0 1,68 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#define ARR_SIZE 3
+
+FILE *
+openInputFile(void)
+{
+	FILE *fp = fopen("input.txt","r");
+	if (fp == NULL)
+	{
+		printf("Could not open file: input.txt\n");
+		exit(EXIT_FAILURE);
+	}
+	return fp;
+}
+
+int
+sumArray(int *array, int size)
+{
+	int sum = 0;
+	for (int i = 0; i < size; i++)
+		sum += array[i];
+	return sum;
+}
+
+int
+main(void)
+{
+	FILE *fp = openInputFile();
+	int increases = 0;
+
+	int array[ARR_SIZE] = { 0 };
+	int arrayPosition = 0;
+	int currentSum = 0;
+	int previousSum = 0;
+	int firstFill = 1;
+
+	char *line = NULL;
+	size_t len = 0;
+	ssize_t read;
+	while ((read = getline(&line, &len, fp)) != -1)
+	{
+		if (arrayPosition == ARR_SIZE) {
+			if (firstFill)
+				previousSum = currentSum;
+			firstFill = 0;
+			arrayPosition = 0;
+		}
+
+		currentSum = sumArray(array, ARR_SIZE);
+		array[arrayPosition++] = atoi(line);
+
+		// Don't do comparisons until we've filled the array
+		if (firstFill)
+			continue;
+
+		if (currentSum > previousSum)
+			increases++;
+		previousSum = currentSum;
+	}
+
+	fclose(fp);
+	if (line)
+		free(line);
+	printf("%d\n", increases);
+	exit(EXIT_SUCCESS);
+}