2020/day12.c


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#include <stdio.h>
#include <stdlib.h>
static void swap(int *a, int *b) {
	int x = *a;
	*a = *b;
	*b = x;
}
int main(void) {
	int x = 0, y = 0;
	int dx = 1, dy = 0;
	char act;
	int val;
	while (0 < scanf("%c%d\n", &act, &val)) {
		switch (act) {
			break; case 'N': y -= val;
			break; case 'S': y += val;
			break; case 'E': x += val;
			break; case 'W': x -= val;
			break; case 'L': {
				for (int i = 0; i < val / 90; ++i) {
					swap(&dx, &dy);
					dy *= -1;
				}
			}
			break; case 'R': {
				for (int i = 0; i < val / 90; ++i) {
					swap(&dx, &dy);
					dx *= -1;
				}
			}
			break; case 'F': x += val * dx; y += val * dy;
		}
	}
	printf("%d\n", abs(x) + abs(y));
}