运行 ID: 129616

Main.cc: In function ‘int main()’:
Main.cc:6:2: error: ‘m’ was not declared in this scope
  m=sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));
  ^
Main.cc:6:2: note: suggested alternative: ‘tm’
  m=sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));
  ^
  tm