Compilare: main.cpp: In function 'int factor()': main.cpp:33:18: warning: array subscript has type 'char' [-Wchar-subscripts] r = fr[nr]; ^ main.cpp: In function 'int main()': main.cpp:74:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<strlen(v); i++) ~^~~~~~~~~~ main.cpp:111:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i1=0; i1<strlen(var); i1++) ~~^~~~~~~~~~~~