void hld(int node, int par){
if(chain_head[chain_no] == -1) chain_head[chain_no] = node; //assigning the head
chain_idx[node] = chain_no;
chain_pos[node] = chain_size[chain_no];
chain_size[chain_no]++;
int idx = -1;
int sub_sz = -1;
for(auto v : g[node]){
if(v == par) continue;
if(sz[v] > sub_sz){
idx = v;
sub_sz = sz[v];
}
}
if(idx != -1) hld(idx, node);
for(auto v : g[node]){
if(v == par) continue;
if(v != idx){
chain_no++;
hld(v, node);
}
}
}
// gives a 1-index to each node such that indices
// in each heavy path are contiguous
void hld(int u, int p = 0) {
static int index = 0;
hld_index[u] = ++index;
hld_order[hld_index[u]] = X[u];
if (!hld_root[u]) hld_root[u] = u;
if (hld_child[u]) {
hld_root[hld_child[u]] = hld_root[u];
hld(hld_child[u], u);
}
for (auto v : g[u]) if (v != p && v != hld_child[u])
hld(v, u);
}
void bin_index_t::save_items_count()
{
fs::path file_name=fs::path(base_dir)/items_count_file_name;
FILE* f=fopen(file_name.string().c_str(),"wb");
if(!f)throw std::runtime_error("could not open items count file for write: "+file_name.string());
file_hldr hld(f);
#ifdef _WIN32
if(fprintf(f,"%u",items_count)<0)
#else
if(fprintf(f,"%llu",items_count)<0)
#endif
throw std::runtime_error("could not write items count: "+file_name.string());
}
void hld(int cur) {
if(chainHead[chainNo] == -1) chainHead[chainNo]=cur;
chainInd[cur] = chainNo;
chainPos[cur] = chainSize[chainNo];
chainSize[chainNo]++;
int ind = -1,mai = -1;
for(int i = 0; i < adj[cur].sz; i++) {
if(subsize[ adj[cur][i] ] > mai) {
mai = subsize[ adj[cur][i] ];
ind = i;
}
}
if(ind >= 0) hld( adj[cur][ind] );
for(int i = 0; i < adj[cur].sz; i++) {
if(i != ind) {
chainNo++;
hld( adj[cur][i] );
}
}
}
void bin_index_t::load_items_count()
{
fs::path file_name=fs::path(base_dir)/items_count_file_name;
if(!fs::exists(file_name))return;
FILE* f=fopen(file_name.string().c_str(),"rb");
if(!f)throw std::runtime_error("could not open items count file for read: "+file_name.string());
file_hldr hld(f);
#ifdef _WIN32
if(fscanf(f,"%u",&items_count)!=1)
#else
if(fscanf(f,"%lluu",&items_count)!=1)
#endif
throw std::runtime_error("could not read items count: "+file_name.string());
}
