Eroare de compilare: user.cpp: In member function ‘double point_data_t::len()’: user.cpp:25:24: error: ‘sqrt’ was not declared in this scope return sqrt(sqr_len()); ^ user.cpp: In function ‘int main()’: user.cpp:222:27: error: ‘sqrt’ was not declared in this scope fprintf(g,"%.7f",sqrt(ans)); ^ user.cpp:208:19: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&N); ^ user.cpp:211:38: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%lf %lf",&V[i].x,&V[i].y); ^