From f6d1527ef4283024f33181b1aa614b94e7c743e9 Mon Sep 17 00:00:00 2001 From: Curtis McEnroe Date: Tue, 4 Dec 2018 21:06:59 -0500 Subject: Solve day 4 part 1 --- 2018/day04.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) create mode 100644 2018/day04.c (limited to '2018') diff --git a/2018/day04.c b/2018/day04.c new file mode 100644 index 0000000..5d2939f --- /dev/null +++ b/2018/day04.c @@ -0,0 +1,45 @@ +#include +#include +#include + +typedef unsigned uint; + +enum { Len = 4096 }; +uint guards[Len][60]; + +int main() { + uint id, sleep; + while (!feof(stdin)) { + uint year, month, day, hour, minute; + char word[256]; + scanf( + "[%u-%u-%u %u:%u] %255s #%u", + &year, &month, &day, &hour, &minute, word, &id + ); + scanf("%*[^\n]\n"); + + if (!strcmp(word, "falls")) sleep = minute; + if (!strcmp(word, "wakes")) { + for (uint m = sleep; m < minute; ++m) { + guards[id][m]++; + } + } + } + uint maxID = 0, maxSum = 0; + for (uint i = 0; i < Len; ++i) { + uint sum = 0; + for (uint m = 0; m < 60; ++m) { + sum += guards[i][m]; + } + if (sum < maxSum) continue; + maxSum = sum; + maxID = i; + } + uint maxMin = 0, maxSleep = 0; + for (uint m = 0; m < 60; ++m) { + if (guards[maxID][m] < maxSleep) continue; + maxSleep = guards[maxID][m]; + maxMin = m; + } + printf("%u\n", maxID * maxMin); +} -- cgit 1.4.1