Compilare: main.cpp: In function 'void update(unsigned int, int)': main.cpp:62:16: 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:108:36: 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:110:38: 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:116:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ main.cpp:120:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &v[i]); ^