Compilare: user.cpp: In function ‘void update(int, int)’: user.cpp:14:10: warning: statement has no effect [-Wunused-value] for(i; i <= n; i += i & -i) ^ user.cpp: In function ‘int sum(int)’: user.cpp:21:10: warning: statement has no effect [-Wunused-value] for(i; i > 0; i -= i & -i) ^ user.cpp: In function ‘int main()’: user.cpp:29:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(inFile, "r", stdin); ^ user.cpp:30:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(outFile, "w", stdout); ^ user.cpp:31:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:33:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &x); ^ user.cpp:37:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &x, &a, &b); ^