Eroare de compilare: main.cpp: In function 'double len(std::pair<double, double>, std::pair<double, double>)': main.cpp:26:100: error: 'sqrt' was not declared in this scope return sqrt ((x.first-y.first) * (x.first-y.first) + (x.second-y.second) * (x.second-y.second) ); ^ main.cpp: In function 'int main()': main.cpp:34:25: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%d",&t); ^ main.cpp:36:29: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%d",&r); ^ Non zero exit status: 1