Compilare: main.cpp: In function 'int main()': main.cpp:59:38: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 59 | for (int k = 0;k < s.size();k++) { | ~~^~~~~~~~~~ main.cpp:71:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 71 | for (int i = 0;i < s.size();i++) | ~~^~~~~~~~~~ main.cpp:72:30: 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 (int j = 0;j < s.size();j++) | ~~^~~~~~~~~~ main.cpp:76:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 76 | for (int i = 0;i < s.size();i++) | ~~^~~~~~~~~~ main.cpp:82:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 82 | for (int k = 0;k < s.size();k++) | ~~^~~~~~~~~~ main.cpp:87:34: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 87 | for (int k = 0;k < s.size();k++) | ~~^~~~~~~~~~ main.cpp:100:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 100 | for (int l = 1;l < s.size();l++) { | ~~^~~~~~~~~~ main.cpp:101:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 101 | for (int k = 0;k < s.size() - l;k++) { | ~~^~~~~~~~~~~~~~