Compilare: user.cpp: In function ‘int main()’: user.cpp:11:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("texttrim.in","r",stdin); ^ user.cpp:12:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("texttrim.out","w",stdout); ^ user.cpp:14:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&v[i]); ^ user.cpp:15:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%c",&c); ^ user.cpp:16:12: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s);n=strlen(s); ^ user.cpp:17:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&w); ^ /tmp/ccVviYH0.o: In function `main': user.cpp:(.text.startup+0x8f): warning: the `gets' function is dangerous and should not be used.