Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:42:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=2;i<=l[k].size();i++) ^ user.cpp:43:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=1;j+i-1<=l[k].size();j++) ^ user.cpp:54:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=2;i<=s[1].size();i++) ^ user.cpp:55:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=1;j+i-1<=s[1].size();j++) ^ user.cpp: In function ‘void read()’: user.cpp:15:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:18:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&x); ^ user.cpp: In function ‘int main()’: user.cpp:69:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("petsoft.in","r",stdin); ^ user.cpp:70:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("petsoft.out","w",stdout); ^