Compilare: user.cpp: In function ‘int sfd(int)’: user.cpp:34:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int dfs(int)’: user.cpp:51:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int add(int, int)’: user.cpp:64:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int main()’: user.cpp:68:28: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d%d",&n,&m); ^ user.cpp:73:32: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d%d",&a,&b); ^