Compilare: main.cpp: In function 'int main()': main.cpp:35:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(pos[i].size() <= rad) ~~~~~~~~~~~~~~^~~~~~ main.cpp:37:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < pos[i].size(); ++j) ~~^~~~~~~~~~~~~~~ main.cpp:39:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k = j; k < pos[i].size(); ++k) ~~^~~~~~~~~~~~~~~ main.cpp:54:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(k + 1 == pos[i].size()) ~~~~~~^~~~~~~~~~~~~~~~