Compilare: user.cpp: In function ‘int check(int)’: user.cpp:9:9: warning: unused variable ‘j’ [-Wunused-variable] int i, j, t = 1, p = 0, val = 0; ^ user.cpp: In function ‘void read_and_solve()’: user.cpp:21:9: warning: unused variable ‘j’ [-Wunused-variable] int i, j, k; long d = 0; ^ user.cpp:21:12: warning: unused variable ‘k’ [-Wunused-variable] int i, j, k; long d = 0; ^ user.cpp:22:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &N), NR = 0; ^ user.cpp:23:62: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(i = 1; i <= N; i++) scanf("%d ", &A[i]), d += (long)A[i]; ^ user.cpp: In function ‘int main()’: user.cpp:32:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("auto.in", "rt", stdin); ^ user.cpp:33:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("auto.out", "wt", stdout); ^ user.cpp:34:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d ", &teste); ^