Compilare: main.cpp: In function 'int main()': main.cpp:19:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<sir.length();i++) ~^~~~~~~~~~~~~ main.cpp:35:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<=sir.length();i++) ~^~~~~~~~~~~~~~ main.cpp:50:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<=sir.length();i++) ~^~~~~~~~~~~~~~