Compilare: user.cpp: In function ‘int main()’: user.cpp:45:12: warning: unused variable ‘i’ [-Wunused-variable] int n, i, l; ^ user.cpp:45:15: warning: unused variable ‘l’ [-Wunused-variable] int n, i, l; ^ user.cpp: In function ‘void process(expression&)’: user.cpp:99:33: warning: array subscript has type ‘char’ [-Wchar-subscripts] e.v_index[e.s[i]] = e.nvar; ^ user.cpp:104:70: warning: array subscript has type ‘char’ [-Wchar-subscripts] while(!stk.empty() && stk.top() != '(' && prior[stk.top()] >= prior[e.s[i]] && e.s[i] != '~') { ^ user.cpp:104:87: warning: array subscript has type ‘char’ [-Wchar-subscripts] while(!stk.empty() && stk.top() != '(' && prior[stk.top()] >= prior[e.s[i]] && e.s[i] != '~') { ^ user.cpp: In function ‘bool are_same(expression&, expression&)’: user.cpp:118:12: warning: unused variable ‘j’ [-Wunused-variable] int i, j; ^ user.cpp:119:10: warning: unused variable ‘found’ [-Wunused-variable] bool found, val1, val2; ^ user.cpp: In function ‘bool getVal(expression&, char)’: user.cpp:153:35: warning: array subscript has type ‘char’ [-Wchar-subscripts] return gen & (1 << e.v_index[x]); ^ user.cpp: In function ‘int main()’: user.cpp:37:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(inFile, "r", stdin); ^ user.cpp:38:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(outFile, "w", stdout); ^ user.cpp:47:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &n); ^ user.cpp:52:19: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(e1.s); ^ user.cpp:56:19: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(e2.s); ^ user.cpp: In function ‘bool eval(expression&)’: user.cpp:210:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ /tmp/ccXK7r6y.o: In function `main': user.cpp:(.text.startup+0xbb): warning: the `gets' function is dangerous and should not be used.