Compilare: user.cpp: In function ‘int solve()’: user.cpp:14:9: warning: unused variable ‘sol’ [-Wunused-variable] int sol=0; ^ user.cpp: In function ‘void read()’: user.cpp:7:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("fsb.in","r",stdin); ^ user.cpp:8:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n",&N); ^ user.cpp:9:14: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(sir); ^ user.cpp: In function ‘int main()’: user.cpp:26:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("fsb.out","w",stdout); ^ /tmp/ccRzDlFF.o: In function `read()': user.cpp:(.text+0x44): warning: the `gets' function is dangerous and should not be used.