Awesomeness

4 files changed, 194 insertions, 61 deletions

diff --git a/2020/10/Makefile b/2020/10/Makefile
new file mode 100644
index 0000000..769d06d
--- /dev/null
+++ b/2020/10/Makefile
@@ -0,0 +1,10 @@
+.PHONY: solve.c
+
+solve.o: solve.c
+	@gcc $+ -o $@
+
+clean:
+	@rm -f *.o
+
+run: solve.o
+	@./solve.o
diff --git a/2020/10/Program.cs b/2020/10/Program.cs
deleted file mode 100644
index 16ef0ff..0000000
--- a/2020/10/Program.cs
+++ /dev/null
@@ -1,37 +0,0 @@
-using System;

-using System.IO;

-using System.Linq;

-

-namespace AOC

-{

-    internal class Run

-    {

-        private static int PartOne(int[] data)

-        {

-            int prev = 0, three = 1, one = 0;

-            for (int i = 0; i < data.Length; i++)

-            {

-                if (data[i] - prev == 3) three++;

-                else one++;

-

-                prev = data[i];

-            }

-

-            return one * three;

-        }

-        

-        private static int PartTwo(int[] data)

-        {

-            return 0;

-        }

-

-        public static void Main(string[] args)

-        {

-            string text = File.ReadAllText(@"C:\Users\bornerma\Desktop\input.txt");

-            string[] numsStr = text.Split('\n');

-            int[] nums = Array.ConvertAll(numsStr, int.Parse).OrderBy(i => i).ToArray();

-            Console.WriteLine(PartOne(nums));

-            Console.WriteLine(PartTwo(nums));

-        }

-    }

-}
\ No newline at end of file
diff --git a/2020/10/input b/2020/10/input
index be5c492..922358c 100644
--- a/2020/10/input
+++ b/2020/10/input
@@ -1,31 +1,111 @@
-28
-33
+71
+183
+111
+89
+92
+142
+25
+101
+52
+86
 18
-42
-31
-14
-46
-20
-48
-47
+22
+70
+2
+135
+163
+34
+143
+153
+35
+144
 24
 23
-49
-45
-19
+94
+100
+102
+17
+57
+76
+182
+134
 38
-39
+7
+103
+66
+31
 11
-1
+121
+77
+113
+128
+82
+99
+148
+137
+41
 32
-25
-35
-8
-17
-7
-9
-4
-2
-34
+48
+131
+60
+127
+138
+73
+28
 10
-3
\ No newline at end of file
+84
+180
+63
+125
+53
+176
+165
+114
+145
+152
+72
+107
+167
+59
+164
+78
+126
+118
+136
+83
+79
+58
+14
+106
+69
+51
+39
+157
+42
+177
+173
+93
+141
+3
+33
+13
+19
+45
+154
+95
+170
+54
+181
+6
+151
+1
+112
+96
+115
+85
+108
+166
+160
+40
+122
+12
\ No newline at end of file
diff --git a/2020/10/solve.c b/2020/10/solve.c
new file mode 100644
index 0000000..83c5535
--- /dev/null
+++ b/2020/10/solve.c
@@ -0,0 +1,80 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+static int LENGTH = 0;
+
+int part_one(int *data)
+{
+	int prev = 0, three = 1, one = 0;
+
+	for (int i = 0; i < LENGTH; i++) {
+		if (data[i] == 0)
+			continue;
+		if (data[i] - prev == 3)
+			three++;
+		else
+			one++;
+		prev = data[i];
+	}
+
+	return one * three;
+}
+
+long part_two(int *data)
+{
+	long a, b, c;
+	a = 1;
+	b = 0;
+	c = 0;
+	for (int i = LENGTH - 2; i > 0; i--) {
+		long next = (i + 1 < LENGTH && data[i + 1] - data[i] <= 3 ? a : 0) +
+			    (i + 2 < LENGTH && data[i + 2] - data[i] <= 3 ? b : 0) +
+			    (i + 3 < LENGTH && data[i + 3] - data[i] <= 3 ? c : 0);
+		c = b;
+		b = a;
+		a = next;
+	}
+
+	return a;
+}
+
+int cmp(const void *a, const void *b)
+{
+	int int_a = *((int *)a);
+	int int_b = *((int *)b);
+
+	if (int_a == int_b)
+		return 0;
+	else if (int_a < int_b)
+		return -1;
+	else
+		return 1;
+}
+
+int *to_int(FILE *fp, int *arr)
+{
+	int d = 0, i = 0;
+	while (fscanf(fp, "%d\n", &d) != EOF)
+		arr[i++] = d;
+	LENGTH = i + 2;
+
+	return arr;
+}
+
+int main()
+{
+	FILE *fp = fopen("input", "r");
+	if (!fp)
+		exit(EXIT_FAILURE);
+
+	int data[128] = { 0 };
+	to_int(fp, data);
+	qsort(data, LENGTH, sizeof(int), cmp);
+	data[LENGTH] = data[LENGTH - 1] + 3;
+
+	printf("%d\n", part_one(data));
+	printf("%lu\n", part_two(data));
+
+	fclose(fp);
+	return 0;
+}