Compilare: user.cpp: In function ‘int main()’: user.cpp:39:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("potrivire.in","r",stdin); ^ user.cpp:40:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("potrivire.out","w",stdout); ^ user.cpp:41:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%c",&n,&M,&c); ^ user.cpp:42:15: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s1+1);gets(s2+1); ^ user.cpp:42:26: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s1+1);gets(s2+1); ^ /tmp/ccIXXa1J.o: In function `main': user.cpp:(.text.startup+0x7a): warning: the `gets' function is dangerous and should not be used.