Solve day 5 part 2

1 files changed, 9 insertions, 0 deletions

diff --git a/2020/day05.c b/2020/day05.c
index 8d87fcb..ab39815 100644
--- a/2020/day05.c
+++ b/2020/day05.c
@@ -1,3 +1,4 @@
+#include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 static int id(const char *s) {
@@ -16,8 +17,16 @@ static int id(const char *s) {
 int main(void) {
 	char s[11];
 	int max = 0;
+	bool ids[1024] = {0};
 	while (EOF != scanf("%s\n", s)) {
 		if (id(s) > max) max = id(s);
+		ids[id(s)] = true;
 	}
 	printf("%d\n", max);
+	for (int i = 1; i < 1024; ++i) {
+		if (ids[i-1] && !ids[i]) {
+			printf("%d\n", i);
+			break;
+		}
+	}
 }