Compilare: user.cpp: In function ‘int cmmdc(int, int)’: user.cpp:11:15: warning: suggest parentheses around assignment used as truth value [-Wparentheses] while(r=a%b){ ^ user.cpp: In function ‘int main()’: user.cpp:19:15: warning: unused variable ‘t’ [-Wunused-variable] int a,b,x,t; ^ user.cpp:20:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("holiday.in","r",stdin); ^ user.cpp:21:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("holiday.out","w",stdout); ^ user.cpp:39:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&a,&b,&x); ^