Compilare: main.cpp: In function 'int main()': main.cpp:40:23: warning: unused variable 'a' [-Wunused-variable] long long a = abs(p[i].x - p[j].x); ^ main.cpp:63:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < dr.size() - 1; ++i) ~~^~~~~~~~~~~~~~~ main.cpp:64:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = i + 1; j < dr.size(); ++j){ ~~^~~~~~~~~~~