ez

3 files changed, 149 insertions, 0 deletions

diff --git a/2020/22/Makefile b/2020/22/Makefile
new file mode 100644
index 0000000..fc2ff1a
--- /dev/null
+++ b/2020/22/Makefile
@@ -0,0 +1,10 @@
+.PHONY: solve.c
+
+solve.o: solve.c
+	@gcc -Ofast $+ -o $@
+
+clean:
+	@rm -f *.o
+
+run: solve.o
+	@./solve.o
diff --git a/2020/22/input b/2020/22/input
new file mode 100644
index 0000000..3a7ee9a
--- /dev/null
+++ b/2020/22/input
@@ -0,0 +1,53 @@
+Player 1:
+50
+19
+40
+22
+7
+4
+3
+16
+34
+45
+46
+39
+44
+32
+20
+29
+15
+35
+41
+2
+21
+28
+6
+26
+48
+
+Player 2:
+14
+9
+37
+47
+38
+27
+30
+24
+36
+31
+43
+42
+11
+17
+18
+10
+12
+5
+33
+25
+8
+23
+1
+13
+49
diff --git a/2020/22/solve.c b/2020/22/solve.c
new file mode 100644
index 0000000..ce8c992
--- /dev/null
+++ b/2020/22/solve.c
@@ -0,0 +1,86 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+long part_one(FILE *fp)
+{
+	long res = 0;
+
+	int player_one[512] = { 0 }, player_two[512] = { 0 };
+	int one_low = 0, one_high = 0, two_low = 0, two_high = 0;
+
+	char *line = NULL;
+	size_t len;
+	int paragraph = 0;
+	int index = 0;
+	while (getline(&line, &len, fp) != -1) {
+		if (line[0] == '\n') {
+			index = 0;
+			paragraph++;
+			continue;
+		} else if (line[0] == 'P') {
+			continue;
+		} else {
+			int num;
+			sscanf(line, "%d", &num);
+			if (paragraph == 0)
+				player_one[index++] = num;
+			else
+				player_two[index++] = num;
+		}
+	}
+
+	one_high = two_high = index;
+
+	int cnt = 0;
+	while (1) {
+		int c1 = player_one[one_low++];
+		int c2 = player_two[two_low++];
+		cnt++;
+
+		if (!c1 || !c2)
+			break;
+
+		if (c1 > c2) {
+			player_one[one_high++] = c1;
+			player_one[one_high++] = c2;
+		} else {
+			player_two[two_high++] = c2;
+			player_two[two_high++] = c1;
+		}
+	}
+
+	int *winner = one_low == one_high + 1 ? player_two : player_one;
+	int low = one_low == one_high + 1 ? two_low : one_low;
+	int high = one_low == one_high + 1 ? two_high : one_high;
+
+	for (int i = high - low + 1, j = 0; i > 0; i--, j++)
+		res += i * winner[two_low + j - 1];
+
+	return res;
+}
+
+long part_two(FILE *fp)
+{
+	long res = 0;
+
+	return res;
+}
+
+int main(int argc, char *argv[])
+{
+	FILE *fp = fopen("input", "r");
+	if (!fp)
+		exit(EXIT_FAILURE);
+
+	clock_t tic = clock();
+	printf("%lu\n", part_one(fp));
+	rewind(fp);
+	printf("%lu\n", part_two(fp));
+	clock_t toc = clock();
+	printf("TIME: %f seconds\n", (double)(toc - tic) / CLOCKS_PER_SEC);
+
+	fclose(fp);
+	return 0;
+}