Compilare: user.cpp: In function ‘int main()’: user.cpp:38:8: warning: unused variable ‘x’ [-Wunused-variable] int j,x,y; ^ user.cpp:38:10: warning: unused variable ‘y’ [-Wunused-variable] int j,x,y; ^ user.cpp:36:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("arb.in", "r", stdin); ^ user.cpp:37:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("arb.out", "w", stdout); ^ user.cpp:40:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &N); ^ user.cpp:41:48: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for (int i = 0; i < N; ++i) scanf("%d", &c[i]); ^ user.cpp:42:66: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for (int i = 1; i < N; ++i) scanf("%d",&j), No[j-1].push_back(i); ^ user.cpp:44:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &q); ^ user.cpp:46:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &Q1[j], &LVL[j]); ^