1 files changed, 70 insertions, 0 deletions
diff --git a/2020/2/solve.c b/2020/2/solve.c
new file mode 100644
index 0000000..66f5577
--- /dev/null
+++ b/2020/2/solve.c
@@ -0,0 +1,70 @@
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+int part_one()
+{
+	FILE *fp = fopen("input", "r");
+	if (!fp)
+		exit(EXIT_FAILURE);
+
+	int res = 0;
+
+	char *line = NULL;
+	size_t len = 0;
+	ssize_t read = 0;
+	while ((read = getline(&line, &len, fp)) != -1) {
+		(void)read;
+		int low, high, cnt = 0;
+		char ch;
+		char str[256];
+		sscanf(line, "%d-%d %c: %s\n", &low, &high, &ch, &str[0]);
+		for (int i = 0; i < strlen(str); i++) {
+			if (str[i] == ch) {
+				cnt++;
+			}
+		}
+		if (cnt >= low && cnt <= high)
+			res++;
+	}
+
+	fclose(fp);
+
+	return res;
+}
+
+int part_two()
+{
+	FILE *fp = fopen("input", "r");
+	if (!fp)
+		exit(EXIT_FAILURE);
+
+	int res = 0;
+
+	char *line = NULL;
+	size_t len = 0;
+	ssize_t read = 0;
+	while ((read = getline(&line, &len, fp)) != -1) {
+		(void)read;
+		int low, high, cnt = 0;
+		char ch, first, second;
+		char str[256];
+		sscanf(line, "%d-%d %c: %s\n", &low, &high, &ch, &str[0]);
+		first = str[low - 1];
+		second = str[high - 1];
+		if (first == ch && second != ch || first != ch && second == ch)
+			res++;
+	}
+
+	fclose(fp);
+
+	return res;
+}
+
+int main(int argc, char *argv[])
+{
+	printf("%d\n", part_one());
+	printf("%d\n", part_two());
+	return 0;
+}