Compilare: main.cpp: In function 'int main()': main.cpp:69:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j=1; j<=gr[i].size(); j++){ ~^~~~~~~~~~~~~~ main.cpp:73:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j=0; j<gr[i].size(); j++){ ~^~~~~~~~~~~~~ main.cpp:78:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j=0; j<gr[i].size(); j++){ ~^~~~~~~~~~~~~ main.cpp:81:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int l=1; l<=gr[i].size(); l++){ ~^~~~~~~~~~~~~~ main.cpp:108:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j=1; j<=gr[i].size(); j++){ ~^~~~~~~~~~~~~~ main.cpp:99:16: warning: unused variable 'ans' [-Wunused-variable] long long ans = 2e9 + 1; ^~~