Eroare de compilare: main.cpp: In function 'int main()': main.cpp:19:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 19 | for (j = 0; j < s.size(); j++) | ~~^~~~~~~~~~ main.cpp:55:13: error: 'sum' was not declared in this scope 55 | sum += a[j] * b[j] * h[i][j]; | ^~~ main.cpp:57:13: error: 'sum' was not declared in this scope 57 | fout << sum; | ^~~ Non zero exit status: 1