Compilare: main.cpp: In function 'int main()': main.cpp:62:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 62 | for (i = 0; i < s1.size(); ++i) { | ~~^~~~~~~~~~~ main.cpp:67:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 67 | for (i = 0; i < s2.size(); ++i) { | ~~^~~~~~~~~~~ main.cpp:72:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 72 | for (i = 0; i < s3.size(); ++i) { | ~~^~~~~~~~~~~ main.cpp:25:9: warning: unused variable 'n' [-Wunused-variable] 25 | int n, i, node, cost; | ^ main.cpp:25:21: warning: variable 'cost' set but not used [-Wunused-but-set-variable] 25 | int n, i, node, cost; | ^~~~