运行 ID: 129593

Main.cc: In function ‘int main()’:
Main.cc:7:9: error: ‘sqrt’ was not declared in this scope
     ans=sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));
         ^~~~
Main.cc:7:9: note: suggested alternative: ‘qsort’
     ans=sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));
         ^~~~
         qsort