Compilare: user.cpp: In function ‘int prefsuf_unc(int)’: user.cpp:53:12: warning: unused variable ‘k’ [-Wunused-variable] int j, k, p; ^ user.cpp: In function ‘void solve()’: user.cpp:113:31: warning: suggest parentheses around assignment used as truth value [-Wparentheses] if (k = prefsuf_unc(i)) ^ user.cpp:84:10: warning: unused variable ‘ok’ [-Wunused-variable] bool ok; ^ user.cpp: In function ‘void read()’: user.cpp:10:54: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("infinitepatternmatching.in", "r", stdin); ^ user.cpp:11:16: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s + 1); ^ user.cpp: In function ‘void write()’: user.cpp:125:56: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("infinitepatternmatching.out", "w", stdout); ^ /tmp/ccNLMViB.o: In function `read()': user.cpp:(.text+0x30): warning: the `gets' function is dangerous and should not be used.