Compilare: user.cpp: In function ‘int main()’: user.cpp:9:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cristale.in","r",stdin); ^ user.cpp:10:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cristale.out","w",stdout); ^ user.cpp:11:47: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%c %c %c\n%d",&v[1],&v[2],&v[3],&t); ^ user.cpp:14:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d ",&n); p=0; ^ user.cpp:15:18: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s+1); w[1]=0; w[2]=0; w[3]=0; ^ /tmp/ccKjVX3t.o: In function `main': user.cpp:(.text.startup+0xbc): warning: the `gets' function is dangerous and should not be used.