Compilare: main.cpp: In function 'int main()': main.cpp:73:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 73 | for (i = 0; i < x.size(); i++) | ~~^~~~~~~~~~ main.cpp:90:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 90 | for (int k = 1; k <= x.size(); k++) | ~~^~~~~~~~~~~ main.cpp:91:39: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 91 | for (int y = 1; y <= x.size(); y++) | ~~^~~~~~~~~~~ main.cpp:103:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 103 | for (i = 2; i <= x.size(); i++) | ~~^~~~~~~~~~~ main.cpp:104:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 104 | for (j = 0; j + i <= x.size(); j++) | ~~~~~~^~~~~~~~~~~