Compilare: main.cpp: In function 'int main()': main.cpp:90:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < og.length(); i ++) ~~^~~~~~~~~~~~~ main.cpp:105:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < st.length(); i ++) ~~^~~~~~~~~~~~~ main.cpp: In function 'bool ans()': main.cpp:67:12: warning: 'ret' may be used uninitialized in this function [-Wmaybe-uninitialized] return ret; ^~~