Compilare: main.cpp: In function 'std::__cxx11::string combine(std::__cxx11::string, std::__cxx11::string)': main.cpp:14:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i < A.size() && j < B.size()){ ~~^~~~~~~~~~ main.cpp:14:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i < A.size() && j < B.size()){ ~~^~~~~~~~~~ main.cpp:17:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k = i; k < A.size(); k++) ~~^~~~~~~~~~ main.cpp:24:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(ans == tmp.size() + 1 + A.size() - j) ~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.cpp:29:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(j < B.size()) tmp.push_back(B[j]), j++; ~~^~~~~~~~~~ main.cpp:30:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i < A.size()) tmp.push_back(A[i]), i++; ~~^~~~~~~~~~ main.cpp: In function 'int query(std::__cxx11::string)': main.cpp:8:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &ans); ^ main.cpp: In function 'std::__cxx11::string combine(std::__cxx11::string, std::__cxx11::string)': main.cpp:22:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &ans); ^ main.cpp: In function 'int main()': main.cpp:50:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &N, &K); ^