2020/day13.c


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#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
int main(void) {
	int earliest = 0;
	scanf("%d\n", &earliest);
	int buses[128] = {0};
	int len = 0;
	for (;;) {
		int n = scanf("%d,", &buses[len]);
		if (!n) n = scanf("x,");
		if (n < 0) break;
		len++;
	}
	int min = INT_MAX;
	int bus = 0;
	for (int i = 0; i < len; ++i) {
		if (!buses[i]) continue;
		int wait = (earliest / buses[i] + 1) * buses[i] - earliest;
		if (wait < min) {
			min = wait;
			bus = buses[i];
		}
	}
	printf("%d\n", bus * min);
}