洛谷P3690 【模板】Link Cut Tree （动态树）

题目

https://www.luogu.com.cn/problem/P3690

仅仅是存个代码而已，以备复习。。。

代码

#include<cstdio>
#include<cstdlib>
#include<algorithm>
#define maxn (int)(1e5+10)
using namespace std;
int val[maxn];
struct LCT{
	struct node{
		int father,lson,rson,path_parent;
		int sum,tag,size;
	} tree[maxn];
	int cnt;
	private:
		void update(int x){
			tree[x].sum=tree[tree[x].lson].sum^tree[tree[x].rson].sum^val[x];
			tree[x].size=tree[tree[x].lson].size+tree[tree[x].rson].size+1;
		}
		void pushdown(int x){
			if(tree[x].tag){
				tree[x].tag=0;
				if(tree[x].lson) tree[tree[x].lson].tag^=1;
				if(tree[x].rson) tree[tree[x].rson].tag^=1;
				swap(tree[x].lson,tree[x].rson);
			}
		}
		void zig(int x){
			int y=tree[x].father;
			tree[x].father=tree[y].father;
			tree[x].path_parent=tree[y].path_parent;
			tree[y].path_parent=0;
			if(tree[y].father)
				if(tree[tree[y].father].lson==y) tree[tree[y].father].lson=x;
				else tree[tree[y].father].rson=x;
			int z=tree[x].rson;
			if(z) tree[z].father=y;
			tree[y].lson=z;
			tree[x].rson=y;
			tree[y].father=x;
			update(y);update(x);
		}
		void zag(int x){
			int y=tree[x].father;
			tree[x].father=tree[y].father;
			tree[x].path_parent=tree[y].path_parent;
			tree[y].path_parent=0;
			if(tree[y].father)
				if(tree[tree[y].father].lson==y) tree[tree[y].father].lson=x;
				else tree[tree[y].father].rson=x;
			int z=tree[x].lson;
			if(z) tree[z].father=y;
			tree[y].rson=z;
			tree[x].lson=y;
			tree[y].father=x;
			update(y);update(x);
		}
		void splay(int x){
            pushdown_all(x);
			while(tree[x].father){
				int y=tree[x].father,z=tree[y].father;
				if(!z){
					if(tree[y].lson==x) zig(x);
					else zag(x);
				}
				else{
					if(tree[y].lson==x&&tree[z].lson==y){
						zig(y);zig(x);
					}
					else if(tree[y].rson==x&&tree[z].rson==y){
						zag(y);zag(x);
					}
					else if(tree[y].lson==x&&tree[z].rson==y){
						zig(x);zag(x);
					}
					else{
						zag(x);zig(x);
					}
				}
			}
		}
		void pushdown_all(int x){
			if(tree[x].father) pushdown_all(tree[x].father);
			pushdown(x);
			return;
		}
		void access(int x){
			splay(x);
			if(tree[x].rson){
				tree[tree[x].rson].path_parent=x;
				tree[tree[x].rson].father=0;
				tree[x].rson=0;
				update(x);
			}
			while(tree[x].path_parent){
				int u=tree[x].path_parent;
				splay(u);
				if(tree[u].rson){
					tree[tree[u].rson].path_parent=u;
					tree[tree[u].rson].father=0;
					update(u);
				}
				tree[u].rson=x;
				tree[x].father=u;
				tree[x].path_parent=0;
				update(u);
				x=u;
			}
			splay(x);
		}
		void evert(int x){
			access(x);splay(x);
			tree[x].tag^=1;
			pushdown(x);
		}
		int find_root(int x){
			access(x);splay(x);
			int t=x;
			while(1){
                pushdown(t);
                if(!tree[t].lson) break;
				t=tree[t].lson;
			}
			return t;
		}
	public:
		void link(int x,int y){
			evert(x);
			if(find_root(y)==x) return;
			access(y);splay(y);
			tree[y].father=x;
			tree[x].lson=y;
			update(x);
		}
		void cut(int x,int y){
			evert(x);
			if(find_root(y)!=x) return;
			access(y);splay(y);
            if(tree[y].size>2) return;
			tree[x].father=0;
			tree[y].lson=0;
			update(y);
		}
		int get_sum(int x,int y){
			evert(x);
			access(y);splay(y);
			return tree[y].sum;
		}
		void modify(int x,int y){
			val[x]=y;
			splay(x);
			update(x);
		}
		void insert(int x){
			tree[x].father=tree[x].lson=tree[x].rson=0;
			tree[x].path_parent=0;
			tree[x].size=1;
			tree[x].tag=0;
			tree[x].sum=val[x];
		}
} T;
int main(){
	int i,j,n,m;
	int op,x,y;
    // freopen("T.in","r",stdin);
    // freopen("myans.out","w",stdout);
	scanf("%d%d",&n,&m);
	for(i=1;i<=n;i++)
		scanf("%d",&val[i]);
	for(i=1;i<=n;i++)
		T.insert(i);
	for(i=1;i<=m;i++){
		scanf("%d%d%d",&op,&x,&y);
		if(op==0) printf("%d
",T.get_sum(x,y));
		if(op==1) T.link(x,y);
		if(op==2) T.cut(x,y);
		if(op==3) T.modify(x,y);
	}
    // system("pause");
	return 0;
}