hdu 4010 (LCT模板)

树的节点权值修改,边的分割,边的链接,某两点之间路径上的最大节点权值。

典型的LCT模板题!

我的代码比较冗长,是用以前做别的题的模板修改得来的,所以有些函数没有用到,不过也很有参考价值(遇到别的类似的题,可以直接修改就ok了~),是个很好的模板!

代码如下:

/*
一颗树,有很多操作:
(1)加上边a-b;
(2)将树以a为根,然后删除b和它的父节点的边;
(3)a->b的路径上的所有点权加上d(包含a,b);
(4)查询a->b的路径上最大的点权;
不合法的操作输出-1.
*/
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
using namespace std;
const int INF = 0x3f3f3f3f;
const int MAXN = 300110;
struct Node *null;
struct Node{
	Node *fa,*ch[2];
	int val,size;  //val是该点的权重,size是以它为根的子树的大小。
	int same,add;
	int rev;
	int mm,mmc;
	int sm,smc;
	inline void clear(int _val){  //初始化该点的点权。
		fa = ch[0] = ch[1] = null;
		val = _val; size = 1;
		same = -INF;
		add = 0;
		mm = _val; mmc = 1;
		sm = -INF; smc = 0;
	}
	inline void add_val(int _val,int num){  //权值为val,出现的次数为num
		if(_val == -INF)return;
		if(_val < sm)return;
		if(_val == sm)smc += num;
		else if(_val < mm){
			sm = _val; smc = num;
		}
		else if(_val == mm){
			mmc += num;
		}
		else{
			sm = mm; smc = mmc;
			mm = _val; mmc = num;
		}
	}
	inline void push_up(){
		size = 1 + ch[0]->size + ch[1]->size;
		mm = sm = -INF;
		mmc = smc = 0;
		add_val(val,1);
		add_val(ch[0]->mm,ch[0]->mmc);
		add_val(ch[0]->sm,ch[0]->smc);
		add_val(ch[1]->mm,ch[1]->mmc);
		add_val(ch[1]->sm,ch[1]->smc);
	}
	inline void setc(Node *p,int d){
		ch[d] = p;
		p->fa = this;
	}
	inline bool d(){
		return fa->ch[1] == this;
	}
	inline bool isroot(){
		return fa == null || fa->ch[0] != this && fa->ch[1] != this;
	}
	inline void flip(){
		if(this == null)return;
		swap(ch[0],ch[1]);
		rev ^= 1;
	}
	inline void update_add(int w){
		if(this == null)return;
		if(mm != -INF)mm += w;
		if(sm != -INF)sm += w;
		val += w;
		add += w;
	}
	inline void update_same(int w){
		if(this == null)return;
		mm = w; mmc = size;
		sm = -INF; smc = 0;
		same = w;
		val = w;
		add = 0;
	}
	inline void push_down(){
		if(same != -INF){
			ch[0]->update_same(same);
			ch[1]->update_same(same);
			same = -INF;
		}
		if(add){
			ch[0]->update_add(add);
			ch[1]->update_add(add);
			add = 0;
		}
		if(rev){
			ch[0]->flip();
			ch[1]->flip();
			rev = 0;
		}
	}
	inline void go(){
		if(!isroot())fa->go();
		push_down();
	}
	inline void rot(){
		Node *f = fa, *ff = fa->fa;
		int c = d(), cc = fa->d();
		f->setc(ch[!c],c);
		this->setc(f,!c);
		if(ff->ch[cc] == f)ff->setc(this,cc);
		else this->fa = ff;
		f->push_up();
	}
	inline Node* splay(){
		go();
		while(!isroot()){
			if(!fa->isroot())
				d()==fa->d() ? fa->rot() : rot();
			rot();
		}
		push_up();
		return this;
	}
	inline Node* access(){
		for(Node *p = this,*q = null; p != null; q = p, p = p->fa){
			p->splay()->setc(q,1);
			p->push_up();
		}
		return splay();
	}
	inline Node* find_root(){
		Node *x;
		for(x = access(); x->push_down(), x->ch[0] != null; x = x->ch[0]);
		return x;
	}
	void make_root(){
		access()->flip();
	}
	void cut(){
		access();
		ch[0]->fa = null;
		ch[0] = null;
		push_up();
	}
	void cut(Node *x){    //删除该节点和x之间的边。
		if(this == x || find_root() != x->find_root()) {printf("-1\n");return;}
		else{
			x->make_root();
			cut();
		}
	}
	void link(Node *x){    //该节点链接x节点。(即该节点和x节点之间加一条边)
		if(find_root() == x->find_root()) {printf("-1\n");return;}
		else {
			make_root(); fa = x;
		}
	}
};
void SAME(Node *x,Node *y,int w){    //(2)a->b的路径上的所有点权改为x(包含a,b);
	x->access();
	for(x = null; y != null; x = y, y = y->fa){
		y->splay();
		if(y->fa == null){
			y->ch[1]->update_same(w);
			x->update_same(w);
			y->val = w;
			y->push_up();
			return;
		}
		y->setc(x,1);
		y->push_up();
	}
}
void ADD(Node *x,Node *y,int w){  //(3)a->b的路径上的所有点权加上d(包含a,b);
	x->access();
	for(x = null; y != null; x = y, y = y->fa){
		y->splay();
		if(y->fa == null){
			y->ch[1]->update_add(w);
			x->update_add(w);
			y->val += w;
			y->push_up();
			return;
		}
		y->setc(x,1);
		y->push_up();
	}
}
int MM,MMC;  //最大值,最大值出现的次数
int SM,SMC;  //第二大值,及出现的次数
void ADD_VAL(int val,int num){    //权值为val,出现的次数是num
	if(val == -INF)return;
	if(val < SM)return;
	if(val == SM)SMC += num;
	else if(val < MM){
		SM = val;
		SMC = num;
	}
	else if(val == MM){
		MMC += num;
	}
	else {
		SM = MM; SMC = MMC;
		MM = val; MMC = num;
	}
}
void ask(Node *x,Node *y){    //查询a->b的路径上严格第二大的值,以及它出现的次数;
	x->access();
	for(x=null; y != null; x = y, y = y->fa){
		y->splay();
		if(y->fa == null){
			MM = SM = -INF;
			MMC = SMC = 0;
			ADD_VAL(y->val,1);
			ADD_VAL(y->ch[1]->mm,y->ch[1]->mmc);
			ADD_VAL(y->ch[1]->sm,y->ch[1]->smc);
			ADD_VAL(x->sm,x->smc);
			ADD_VAL(x->mm,x->mmc);
			return;
		}
		y->setc(x,1);
		y->push_up();
	}
}
Node pool[MAXN],*tail;
Node *node[MAXN];
//用来加快建树,防止题目卡时间。
struct Edge{
	int to,next;
}edge[MAXN*2];
int head[MAXN],tot;
void init(){
	tot = 0;
	memset(head,-1,sizeof(head));
}
inline void addedge(int u,int v){
	edge[tot].to = v;
	edge[tot].next = head[u];
	head[u] = tot++;
}
int g[MAXN];
int fa[MAXN];
void bfs(int s){  //用来建树
	int l,r;
	g[l=r=1] = s;
	fa[s] = s;
	while(l <= r){
		int u = g[l++];
		for(int i = head[u];i != -1;i = edge[i].next){
			int v = edge[i].to;
			if(v == fa[u])continue;
			fa[v] = u;
			node[v]->fa = node[u];
			g[++r] = v;
		}
	}
}

int main()
{
    //freopen("in.txt","r",stdin);
    //freopen("out.txt","w",stdout);
	int n,m;
	//scanf("%d",&T);
	while(scanf("%d",&n)!=EOF){
		tail = pool;
		null = tail++;
		null->fa = null->ch[0] = null->ch[1] = null;
		null->size = null->rev = 0;
		null->same = -INF; null->add = 0;
		null->mm = null->sm = -INF;
		null->mmc = null->smc = 0;
		init();
		int u,v;
		for(int i = 1;i < n;i++){
			scanf("%d%d",&u,&v);
			addedge(u,v);  //这里本来可以直接用node[u]->link(node[v]);来直接建边的,但是会慢一点。
			addedge(v,u);
		}
		for(int i = 1;i <= n;i++){
			int v ;
			scanf("%d",&v);  //初始化点权
			node[i] = tail++;
			node[i]->clear(v);
		}
		bfs(1);  //一定要先初始化点权以后再建树!
		scanf("%d",&m);
		int op;
		int x,y,a,b;
		while(m--){
			scanf("%d",&op);
			if(op == 1){
				scanf("%d%d",&a,&b);
				node[a]->link(node[b]);  //a-b建边
			}
			else if(op == 2){
				scanf("%d%d",&a,&b);
				if(a==b||node[a]->find_root()!=node[b]->find_root())
                {
                    printf("-1\n");
                }
                else {
                    node[a]->make_root();  //变为以a为根
				    node[b]->cut(node[b]->fa);  //删掉b和它的父节点的边
                }
            }
			else if(op == 3){
				scanf("%d%d%d",&x,&a,&b);
				if(node[a]->find_root()!=node[b]->find_root())
                {
                    printf("-1\n");
                }
                else
                {
                    ADD(node[a],node[b],x);//(2)a->b的路径上的所有点权加上x(包含a,b);
                }
			}
			else{
				scanf("%d%d",&a,&b);
				if(node[a]->find_root()!=node[b]->find_root())
                {
                    printf("-1\n");
                }
                else
                {
                    ask(node[a],node[b]); 
                    printf("%d\n",MM);
                }
			}
		}
		printf("\n");
	}
    return 0;
}


 

你可能感兴趣的:(数据结构)