foo.cc: In function ‘int main()’:
foo.cc:10:34: warning: unused variable ‘x4’ [-Wunused-variable]
   10 |         double x1,y1,x2,y2,x3,y3,x4,y4,a,b,c;
      |                                  ^~
foo.cc:10:37: warning: unused variable ‘y4’ [-Wunused-variable]
   10 |         double x1,y1,x2,y2,x3,y3,x4,y4,a,b,c;
      |                                     ^~

正在同步测试数据，请稍后