2021/day05.c


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#include <stdio.h>
#include <stdlib.h>
static int sign(int x) {
	return (x > 0 ? 1 : x < 0 ? -1 : 0);
}
int main(void) {
	static int grid[1024][1024];
	static int grid2[1024][1024];
	int x1, y1, x2, y2;
	while (4 == scanf("%d,%d -> %d,%d\n", &x1, &y1, &x2, &y2)) {
		int dx = sign(x2 - x1);
		int dy = sign(y2 - y1);
		for (
			int y = y1, x = x1;
			(dy > 0 ? y <= y2 : y >= y2) && (dx > 0 ? x <= x2 : x >= x2);
			x += dx, y += dy
		) {
			if (x1 == x2 || y1 == y2) grid[y][x]++;
			grid2[y][x]++;
		}
	}
	int points = 0;
	for (int y = 0; y < 1024; ++y)
	for (int x = 0; x < 1024; ++x) {
		if (grid[y][x] > 1) points++;
	}
	printf("%d\n", points);
	points = 0;
	for (int y = 0; y < 1024; ++y)
	for (int x = 0; x < 1024; ++x) {
		if (grid2[y][x] > 1) points++;
	}
	printf("%d\n", points);
}