Compilare: user.c: In function ‘read’: user.c:105:5: warning: implicit declaration of function ‘fgets_unlocked’ [-Wimplicit-function-declaration] fgets_unlocked(buf, sizeof buf, stdin); ^ user.c: In function ‘main’: user.c:126:14: warning: implicit declaration of function ‘getchar_unlocked’ [-Wimplicit-function-declaration] ch = getchar_unlocked(); ^ user.c:120:5: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("heapuri.in", "r", stdin); ^ user.c:121:5: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("heapuri.out", "w", stdout); ^