day 1

1 files changed, 79 insertions, 0 deletions

diff --git a/01.c b/01.c
new file mode 100644
index 0000000..7aba562
--- /dev/null
+++ b/01.c
@@ -0,0 +1,79 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include "input.h"
+
+#define INPUT "input/01.txt"
+#define EXPECTED1 70369L
+#define EXPECTED2 203002L
+
+void part1(struct input_str* input) {
+	// compute max calories
+	long max_calories = 0;
+	long elf_calories = 0;
+	for(size_t i = 0; i < input->line_count; i++) {
+		if(*(input->lines[i]) == '\n') {
+			if(elf_calories > max_calories)
+				max_calories = elf_calories;
+			
+			elf_calories = 0;
+		}
+		int snack_calories = atoi(input->lines[i]);
+		elf_calories += snack_calories;
+	}
+	
+	// input does not end with new line, so one last check
+	if(elf_calories > max_calories)
+		max_calories = elf_calories;
+
+	CHECK(max_calories, EXPECTED1)
+}
+
+void update_max_calories(long elf_calories, long* max1, long* max2, long* max3) {
+	if(elf_calories > *max1) {
+		*max3 = *max2;
+		*max2 = *max1;
+		*max1 = elf_calories;
+	}
+	else if(elf_calories > *max2) {
+		*max3 = *max2;
+		*max2 = elf_calories;
+	}
+	else if(elf_calories > *max3) {
+		*max3 = elf_calories;
+	}
+}
+
+void part2(struct input_str* input) {
+	// compute max calories
+	long max_1_calories = 0;
+	long max_2_calories = 0;
+	long max_3_calories = 0;
+	long elf_calories = 0;
+	for(size_t i = 0; i < input->line_count; i++) {
+		if(*(input->lines[i]) == '\n') {
+			update_max_calories(elf_calories, &max_1_calories, &max_2_calories, &max_3_calories);
+			elf_calories = 0;
+		}
+		int snack_calories = atoi(input->lines[i]);
+		elf_calories += snack_calories;
+	}
+	
+	// input does not end with new line, so one last check
+	update_max_calories(elf_calories, &max_1_calories, &max_2_calories, &max_3_calories);
+
+	CHECK(max_1_calories + max_2_calories + max_3_calories, EXPECTED2)
+}
+
+int main() {
+	// read input
+	struct input_str input;
+	input_str_read(&input, INPUT);
+
+	// do stuff
+	part1(&input);
+	part2(&input);
+
+	// cleanup & exit
+	input_str_free(&input);
+	return 0;
+}