Compilare: user.cpp: In function ‘void CTC(int)’: user.cpp:19:9: warning: unused variable ‘i’ [-Wunused-variable] int i, j, k; ^ user.cpp:19:12: warning: unused variable ‘j’ [-Wunused-variable] int i, j, k; ^ user.cpp: In function ‘int main()’: user.cpp:73:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( j = 1; j < sol[ i ].size(); ++j ) { ^ user.cpp:53:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen( "ctc.in", "r", stdin ); ^ user.cpp:54:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen( "ctc.out", "w", stdout ); ^ user.cpp:58:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf( "%d%d",&n,&m ); ^ user.cpp:60:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf( "%d%d",&x,&y ); ^