Compilare: user.cpp: In function ‘int main()’: user.cpp:77:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("mxl.in", "r", stdin); ^ user.cpp:78:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("mxl.out", "w", stdout); ^ user.cpp:81:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d\n", &n, &k); ^ user.cpp:84:16: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(a); ^ /tmp/ccWxJLYZ.o: In function `main': user.cpp:(.text.startup+0x8a): warning: the `gets' function is dangerous and should not be used.