Compilare: user.cpp: In function ‘void ReadInput()’: user.cpp:23:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); graph.resize(n); key.resize(n); sol.resize(n); idx.resize(n); ^ user.cpp:25:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] int u, v; scanf("%d%d", &u, &v); u--; v--; ^ user.cpp:29:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &key[i]); ^