Compilare: main.cpp: In function 'void update(unsigned int, int)': main.cpp:59:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (; idx <= n; idx += (idx & (~idx + 1))) ~~~~^~~~ main.cpp: In function 'int main()': main.cpp:105:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("scmax.in", "r", stdin); ^ main.cpp:107:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("scmax.out", "w", stdout); ^ main.cpp:113:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ main.cpp:117:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &v[i]); ^