Compilare: user.cpp: In function ‘void Set()’: user.cpp:15:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d ", &n, &m); ^ user.cpp: In function ‘void Solve()’: user.cpp:25:16: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(S); ^ /tmp/ccKd5Rsd.o: In function `Solve()': user.cpp:(.text+0x80): warning: the `gets' function is dangerous and should not be used.