Compilare: user.c: In function ‘read’: user.c:115:18: warning: implicit declaration of function ‘getchar_unlocked’ [-Wimplicit-function-declaration] while ((ch = getchar_unlocked()) != '\n') { ^ user.c: In function ‘write’: user.c:129:9: warning: implicit declaration of function ‘putchar_unlocked’ [-Wimplicit-function-declaration] putchar_unlocked(h[0].x.ch[i]); ^ user.c: In function ‘main’: user.c:138:5: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("heapuri.in", "r", stdin); ^ user.c:139:5: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("heapuri.out", "w", stdout); ^