Compilare: user.cpp: In function ‘void calc(int)’: user.cpp:13:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j,m=0,nrs=0; ^ user.cpp: In function ‘int main()’: user.cpp:80:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("slide.in","r",stdin); ^ user.cpp:81:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("slide.out","w",stdout); ^ user.cpp:84:15: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(si+1); ^ /tmp/ccDF1jm2.o: In function `main': user.cpp:(.text.startup+0x56): warning: the `gets' function is dangerous and should not be used.