Compilare: user.cpp: In function ‘bool solve()’: user.cpp:49:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<exp.size();i++) { ^ user.cpp:51:33: warning: array subscript has type ‘char’ [-Wchar-subscripts] exp[i]=(var[exp[i-1]] || var[exp[i-2]]) + '0'; ^ user.cpp:51:50: warning: array subscript has type ‘char’ [-Wchar-subscripts] exp[i]=(var[exp[i-1]] || var[exp[i-2]]) + '0'; ^ user.cpp:56:33: warning: array subscript has type ‘char’ [-Wchar-subscripts] exp[i]=(var[exp[i-1]] && var[exp[i-2]]) + '0'; ^ user.cpp:56:50: warning: array subscript has type ‘char’ [-Wchar-subscripts] exp[i]=(var[exp[i-1]] && var[exp[i-2]]) + '0'; ^ user.cpp:61:35: warning: array subscript has type ‘char’ [-Wchar-subscripts] exp[i-1]=!var[exp[i-1]]+'0'; ^ user.cpp: In function ‘int main()’: user.cpp:119:23: warning: format ‘%c’ expects argument of type ‘char*’, but argument 2 has type ‘int*’ [-Wformat=] scanf("%c",&ch); ^ user.cpp:72:16: warning: unused variable ‘cnt’ [-Wunused-variable] int n,ch,i,cnt=-1; ^ user.cpp: In function ‘int priority(char)’: user.cpp:17:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ /tmp/cc82IRZx.o: In function `main': user.cpp:(.text.startup+0x4e): warning: the `gets' function is dangerous and should not be used.