3526596_ac_32ms_108k.cpp

北大大牛代码 1240道题的原代码 超级权威

#include <stdio.h>
#include <vector>
#include <algorithm>

using namespace std;

vector <double> x, y;

int main() {
	int n;
	int i;
	double a, b, xx, yy;

	while (scanf("%d", &n) == 1) {
		printf("%d", n);
		x.resize(n);
		y.resize(n);
		x.clear();
		y.clear();
		scanf("%lf%lf", &a, &b);
		xx = a;
		yy = b;
		x.push_back(a);
		y.push_back(b);
		for (i = 1; i < n; i++) {
			scanf("%lf%lf", &a, &b);
			x.push_back(a);
			y.push_back(b);
			if (i % 2 == 1) {
				xx -= a;
				yy -= b;
			} else {
				xx += a;
				yy += b;
			}
		}
		printf(" %.6lf %.6lf", xx, yy);
		for (i = 0; i < n - 1; i++) {
			double tx = x[i] * 2 - xx;
			double ty = y[i] * 2 - yy;
			printf(" %.6lf %.6lf", tx, ty);
			xx = tx;
			yy = ty;
		}
		printf("\n");
	}
	return 0;
}