UVa 10250 另两棵树

/*

* 解题思路:

* 就是求正方形给出两个对角点坐标求出另外两个

*/

#include <stdio.h>int main( ){    double x1,x2,y1,y2,x,y,x3,x4,y3,y4;    while( ~scanf("%lf%lf%lf%lf",&x1,&y1,&x2,&y2 ) )    {         x = (x1+x2)/2;         y = (y1+y2)/2;        x3 = y1 - y + x;        x4 = y - y1 + x;        y3 = x - x1 + y;        y4 = x1 - x + y;        printf("%.10lf %.10lf %.10lf %.10lf\n",x3,y3,x4,y4);    }    return 0;}