Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:26:10: warning: unused variable ‘flag’ [-Wunused-variable] bool flag = 0; ^ user.cpp: In function ‘int main()’: user.cpp:135:9: warning: unused variable ‘sz’ [-Wunused-variable] int sz = 0; ^ user.cpp:108:31: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d %d " ,&n,&m); ^ user.cpp:110:34: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d " ,&val[i]); ^ user.cpp:113:35: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d %d " ,&x,&y); ^