Compilare: main.cpp: In function 'int main()': main.cpp:20:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < s1.size() ; i++) ~~^~~~~~~~~~~ main.cpp:23:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < s.size() ; i++) ~~^~~~~~~~~~ main.cpp:29:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(j < s.size() && isdigit(s[j])) ~~^~~~~~~~~~ main.cpp:39:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < s.size() ; i++) ~~^~~~~~~~~~ main.cpp:48:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < s.size() ; i++) ~~^~~~~~~~~~ main.cpp:62:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < s.size() ; i++) ~~^~~~~~~~~~ main.cpp:18:9: warning: unused variable 'nr' [-Wunused-variable] int nr = 0; ^~