不支持修改的树链剖分

Heavy-Light-Decomposition.cpp

@@ -0,0 +1,223 @@
+#include <cstdio>
+
+#define VERTEX_COUNT 100000
+#define EDGE_COUNT 200000
+
+using namespace std;
+
+struct vertex
+{
+	int first, depth, fa, fae, hson, size, dfn, top;
+}V[VERTEX_COUNT];
+
+struct edge
+{
+	int endp, next, w;
+}E[EDGE_COUNT];
+
+struct segnode
+{
+	segnode *lch, *rch;
+	int sum, lazy;
+	void* operator new (size_t size);
+}segpool[VERTEX_COUNT * 4];
+int segtop = 0;
+
+struct segment_tree
+{
+	segnode *root;
+	int begin, end;
+
+	void build(segnode *&u, int l, int r);
+	void build();
+	void modify(segnode *u, int ul, int ur, int il, int ir, int delta);
+	int query(segnode *u, int ul, int ur, int il, int ir);
+	int query(int il, int ir);
+}seg;
+
+int ivc, ec = 1, dfn = 1, map[VERTEX_COUNT];
+
+void* segnode::operator new (size_t size)
+{
+	return segpool + segtop++;
+}
+
+void segment_tree::build(segnode *&u, int l, int r)
+{
+	u = new segnode;
+	if (l == r)
+	{
+		u->sum = V[map[l]].fae;
+	}
+	else
+	{
+		int mid = (l + r) >> 1;
+		build(u->lch, l, mid);
+		build(u->rch, mid + 1, r);
+		u->sum = u->lch->sum + u->rch->sum;
+	}
+}
+
+void segment_tree::build()
+{
+	build(root, begin, end);
+}
+
+void segment_tree::modify(segnode *u, int ul, int ur, int il, int ir, int delta)
+{
+	if (ul == il && ur == ir)
+	{
+		u->sum += delta * (ur - ul + 1);
+		u->lazy += delta;
+	}
+	else
+	{
+		int mid = (ul + ur) >> 1;
+		if (ir <= mid)
+		{
+			modify(u->lch, ul, mid, il, ir, delta);
+		}
+		else if (il > mid)
+		{
+			modify(u->rch, mid + 1, ur, il, ir, delta);
+		}
+		else
+		{
+			modify(u->lch, ul, mid, il, mid, delta);
+			modify(u->rch, mid + 1, ur, mid + 1, ir, delta);
+		}
+		u->sum += u->lch->sum + u->rch->sum;
+	}
+}
+
+int segment_tree::query(segnode *u, int ul, int ur, int il, int ir)
+{
+	if (ul == il && ur == ir)
+	{
+		return u->sum;
+	}
+	else
+	{
+		int mid = (ul + ur) >> 1;
+		u->lch->sum += u->lazy * (mid - ul + 1);
+		u->lch->lazy += u->lazy;
+		u->rch->sum += u->lazy * (ur - mid);
+		u->rch->lazy += u->lazy;
+		u->lazy = 0;
+		if (ir <= mid)
+		{
+			return query(u->lch, ul, mid, il, ir);
+		}
+		else if (il > mid)
+		{
+			return query(u->rch, mid + 1, ur, il, ir);
+		}
+		else
+		{
+			return query(u->lch, ul, mid, il, mid) + query(u->rch, mid + 1, ur, mid + 1, ir);
+		}
+	}
+}
+
+int segment_tree::query(int il, int ir)
+{
+	return query(root, begin, end, il, ir);
+}
+
+void add_edge(int u, int v, int w)
+{
+	E[ec].next = V[u].first;
+	V[u].first = ec;
+	E[ec].endp = v;
+	E[ec].w = w;
+	ec++;
+}
+
+void DFS1(int u, int depth, int fa, int fae)
+{
+	int hson = 0;
+	V[u].depth = depth;
+	V[u].fa = fa;
+	V[u].fae = fae;
+	V[u].size = 1;
+	for (int cur = V[u].first; cur != 0; cur = E[cur].next)
+	{
+		if (E[cur].endp != fa)
+		{
+			DFS1(E[cur].endp, depth + 1, u, E[cur].w);
+			V[u].size += V[E[cur].endp].size;
+			if (V[E[cur].endp].size > V[hson].size)
+			{
+				hson = E[cur].endp;
+			}
+		}
+	}
+	V[u].hson = hson;
+}
+
+void DFS2(int u, int fa, int top)
+{
+	V[u].dfn = dfn++;
+	map[V[u].dfn] = u;
+	V[u].top = top;
+	if (V[u].hson != 0)
+	{
+		DFS2(V[u].hson, u, top);
+	}
+	for (int cur = V[u].first; cur != 0; cur = E[cur].next)
+	{
+		if (E[cur].endp != V[u].hson && E[cur].endp != fa)
+		{
+			DFS2(E[cur].endp, u, E[cur].endp);
+		}
+	}
+}
+
+int query(int x, int y)
+{
+	int res = 0;
+	while (V[x].top != V[y].top)
+	{
+		int _x = V[x].top == x ? V[x].fa : V[x].top, _y = V[y].top == y ? V[y].fa : V[y].top;
+		if (V[_x].depth < V[_y].depth)
+		{
+			int temp = x;
+			x = y;
+			y = temp;
+		}
+		res += V[x].top == x ? V[x].fae : seg.query(V[V[x].top].dfn + 1, V[x].dfn);
+		x = V[x].top == x ? V[x].fa : V[x].top;
+	}
+	if (V[x].depth > V[y].depth)
+	{
+		res += seg.query(V[y].dfn, V[x].dfn) - V[y].fae;
+	}
+	else
+	{
+		res += seg.query(V[x].dfn, V[y].dfn) - V[x].fae;
+	}
+	return res;
+}
+
+int main()
+{
+	int u, v, w;
+	scanf("%d", &ivc);
+	for (int i = 1; i < ivc; i++)
+	{
+		scanf("%d%d%d", &u, &v, &w);
+		add_edge(u, v, w);
+		add_edge(v, u, w);
+	}
+	DFS1(1, 1, 0, 0);
+	DFS2(1, 0, 1);
+	seg.begin = 1;
+	seg.end = ivc;
+	seg.build();
+	while (true)
+	{
+		scanf("%d%d", &u, &v);
+		printf("%d\n", query(u, v));
+	}
+	return 0;
+}