Compilare: user.cpp: In function ‘int main()’: user.cpp:55:38: warning: array subscript has type ‘char’ [-Wchar-subscripts] while(u2 && op[u2]!='(' && prec[ch[i]]<=prec[op[u2]]) ^ user.cpp:55:52: warning: array subscript has type ‘char’ [-Wchar-subscripts] while(u2 && op[u2]!='(' && prec[ch[i]]<=prec[op[u2]]) ^ user.cpp:10:29: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bool.in","r",stdin); ^ user.cpp:11:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bool.out","w",stdout); ^ user.cpp:13:23: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(ch+1,1002,stdin); ^ user.cpp:67:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n",&t); ^ user.cpp:69:15: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%c",&c); ^