Compilare: user.cpp: In function ‘void formpar(int)’: user.cpp:14:11: warning: statement has no effect [-Wunused-value] for(it; it<strlen(s); it++){ ^ user.cpp:14:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(it; it<strlen(s); it++){ ^ user.cpp: In function ‘int solve(int, int)’: user.cpp:50:9: warning: unused variable ‘ok’ [-Wunused-variable] int ok=0; ^ user.cpp: In function ‘int oper(char, int, int)’: user.cpp:38:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ /tmp/cc4477Qg.o: In function `main': user.cpp:(.text.startup+0x4b): warning: the `gets' function is dangerous and should not be used.