void solve( int lo, int hi ) {
if( lo + 1 == hi ) {
a[lo] = modpow2( a[lo] );
return;
}
int mid = ( lo + hi ) >> 1;
for( int i = lo; i < mid; ++i )
a[mid + i - lo] += a[i];
solve( lo, mid );
solve( mid, hi );
for( int i = lo; i < mid; ++i ) {
a[mid + i - lo] -= a[i];
if( a[mid + i - lo] < 0 ) a[mid + i - lo] += mod;
}
}
size_t cbuf_space_avail(cbuf_t *cbuf)
{
uint consumed = modpow2((uint)(cbuf->head - cbuf->tail), cbuf->len_pow2);
return valpow2(cbuf->len_pow2) - consumed - 1;
}
static inline uint inc_pointer(const cbuf_t* cbuf, uint ptr, uint inc) {
return modpow2(ptr + inc, cbuf->len_pow2);
}
