Compilare: user.cpp: In function ‘int main()’: user.cpp:50:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("scandura.in", "r", stdin); ^ user.cpp:51:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("scandura.out", "w", stdout); ^ user.cpp:53:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &N, &M); ^ user.cpp:67:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%u", &val[i]); ^ user.cpp:76:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%u", &val[i]); ^ user.cpp: In function ‘void solve()’: user.cpp:38:22: warning: ‘wh’ may be used uninitialized in this function [-Wmaybe-uninitialized] ++pbeg[wh]; ^