foo.cc: In function 'int main()':
foo.cc:52:51: error: 'jd' was not declared in this scope
         if((((myabs(l[i][0]-l[i-1][0])/l[i-1][0])+jd<min)||(eq((myabs(l[i][0]-l[i-1][0])/l[i-1][0]),min)&&(myabs(l[i][0]*l[i-1][0])<lb[ia]*lb[ib]*g)))&&(!eq(l[i][1]+l[i-1][1],0.0))&&(l[i][1]*l[i-1][1]<0))
                                                   ^~
foo.cc:52:51: note: suggested alternative: 'jn'
         if((((myabs(l[i][0]-l[i-1][0])/l[i-1][0])+jd<min)||(eq((myabs(l[i][0]-l[i-1][0])/l[i-1][0]),min)&&(myabs(l[i][0]*l[i-1][0])<lb[ia]*lb[ib]*g)))&&(!eq(l[i][1]+l[i-1][1],0.0))&&(l[i][1]*l[i-1][1]<0))
                                                   ^~
                                                   jn

自豪的采用HydroJudge(https://github.com/hydro-dev/Hydro)进行评测。