Compilare: user.cpp: In function ‘int main()’: user.cpp:60:44: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sequencequery.in", "r", stdin); ^ user.cpp:61:46: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sequencequery.out", "w", stdout); ^ user.cpp:63:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d\n", &n, &m); ^ user.cpp:64:45: 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\n", &a[i]); ^ user.cpp:69:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d\n", &x, &y); ^ user.cpp: In function ‘arb query(int, int, int, int, int)’: user.cpp:56:1: warning: control reaches end of non-void function [-Wreturn-type] } ^