Compilare: main.cpp: In function 'int main()': main.cpp:37:27: warning: array subscript has type 'char' [-Wchar-subscripts] 37 | frec[matr[i][j]] = {i, j}; | ~~~~~~~~~^ main.cpp:40:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 40 | for(int k = 0; k < s.size(); k++){ | ~~^~~~~~~~~~ main.cpp:46:26: warning: array subscript has type 'char' [-Wchar-subscripts] 46 | int a = frec[s[k]].first, b = frec[s[k]].second; | ^ main.cpp:46:49: warning: array subscript has type 'char' [-Wchar-subscripts] 46 | int a = frec[s[k]].first, b = frec[s[k]].second; | ^ main.cpp:94:47: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 94 | for(int pla = dr + 1; pla < s.size(); pla++){ | ~~~~^~~~~~~~~~