diff options
| -rw-r--r-- | 2020/day15.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/2020/day15.c b/2020/day15.c new file mode 100644 index 0000000..f5ee806 --- /dev/null +++ b/2020/day15.c @@ -0,0 +1,21 @@ +#include <stdio.h> +#include <stdlib.h> +int main(void) { + int nums[2048]; + int len = 0; + while (0 < scanf("%d,", &nums[len])) { + len++; + } + while (len < 2020) { + int last = nums[len-1]; + int next = 0; + for (int i = len - 2; i >= 0; --i) { + if (nums[i] == last) { + next = len - 1 - i; + break; + } + } + nums[len++] = next; + } + printf("%d\n", nums[len-1]); +} |