Compilare: main.cpp: In function 'int main()': main.cpp:30:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<strlen(s); i++) ~^~~~~~~~~~ main.cpp:35:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(s[i]=='('&&i<strlen(s) ) ~^~~~~~~~~~ main.cpp:41:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(s[i]==')'&&i<strlen(s) ) ~^~~~~~~~~~ main.cpp:48:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(s[i]==' '&&i<strlen(s) ) ~^~~~~~~~~~ main.cpp:52:59: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(strchr("qazxcvbnmlkjhgfdswertyuiop",s[i])&&i<strlen(s) ) ~^~~~~~~~~~ main.cpp:58:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(s[i]==' '&&i<strlen(s) ) ~^~~~~~~~~~ main.cpp:62:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(strchr("1234567890",s[i])&&i<strlen(s) ) ~^~~~~~~~~~