Create 100819V_standard.cpp

Codeforces/Gym/100819V_standard.cpp

@@ -0,0 +1,35 @@
+#include<cstdio>
+int n;
+struct gear { int x, y, r; } a[1024];
+int dir[1024];
+int gcd(int x, int y) { while (y) { int t = x%y; x = y; y = t; } return x; }
+bool fill(int i, int d)
+{
+	dir[i] = d;
+	for (int j = 1; j <= n; j++)
+	{
+		if (i != j && (a[i].x - a[j].x)*(a[i].x - a[j].x)
+			+ (a[i].y - a[j].y)*(a[i].y - a[j].y)
+			== (a[i].r + a[j].r)*(a[i].r + a[j].r))
+		{
+			if (dir[i] == dir[j]) return false;
+			if (dir[j]) continue;
+			if (!fill(j, -d)) return false;
+		}
+	}
+	return true;
+}
+int main()
+{
+	int i;
+	scanf("%d", &n);
+	for (i = 1; i <= n; i++) scanf("%d%d%d", &a[i].x, &a[i].y, &a[i].r);
+	if (!fill(1, 1)) printf("The input gear cannot move.\n");
+	else if (!dir[n]) printf("The input gear is not connected to the output gear.\n");
+	else
+	{
+		int g = gcd(a[1].r, a[n].r);
+		printf("%d:%d\n", a[1].r*dir[n] / g, a[n].r / g);
+	}
+	return 0;
+}