Compilare: main.cpp: In function 'int main()': main.cpp:34:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( i = 1 ; i <= s.size() ; ++ i ) { ~~^~~~~~~~~~~ main.cpp:40:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( i = 0 ; i < s.size() ; ++ i ) { ~~^~~~~~~~~~ main.cpp:50:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( i = s.size() ; i < t.size() ; ++ i ){ ~~^~~~~~~~~~