Compilare: user.c: In function ‘write_int’: user.c:143:9: warning: implicit declaration of function ‘putchar_unlocked’ [-Wimplicit-function-declaration] putchar_unlocked(h[0].x.ch[i]); ^ user.c: In function ‘main’: user.c:151:5: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("heapuri.in", "r", stdin); ^ user.c:152:5: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("heapuri.out", "w", stdout); ^