Compilare: user.cpp: In function ‘void query(long int, long int, long int, long int, long int)’: user.cpp:26:6: warning: suggest parentheses around comparison in operand of ‘&’ [-Wparentheses] if(a<=l & r<=b){ ^ user.cpp: In function ‘int main()’: user.cpp:44:15: warning: unused variable ‘left’ [-Wunused-variable] int l, u, n, left, right,i,j; ^ user.cpp:44:21: warning: unused variable ‘right’ [-Wunused-variable] int l, u, n, left, right,i,j; ^ user.cpp:41:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sum2.in", "r", stdin); ^ user.cpp:42:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sum2.out", "w", stdout); ^ user.cpp:47:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &n, &l, &u); ^ user.cpp:50:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &v[i]); ^