UVALive5031 Graph and Queries(Treap)

反向操作，先求出最终状态，再反向操作。

然后就是Treap 的合并，求第K大值。

#include<cstdio>
#include<iostream>
#include<cstdlib>
#include<cstring>
#include<string>
#include<algorithm>
#include<map>
#include<queue>
#include<vector>
#include<stack>
#include<cmath>
#include<utility>
using namespace std;
typedef long long LL;
struct Treap{
    int size,key,pri;
    Treap *ch[2];
    Treap(int key){
        size=1;
        pri=rand();
        this->key=key;
        ch[0]=ch[1]=NULL;
    }
    int compare(int x) const{
        if(x==key) return -1;
        return x<key? 0:1;
    }
    void Maintain(){
        size=1;
        if(ch[0]!=NULL){
            size+=ch[0]->size;
        }
        if(ch[1]!=NULL){
            size+=ch[1]->size;
        }
    }
};

void Rotate(Treap* &t,int d){
    Treap *k=t->ch[d^1];
    t->ch[d^1]=k->ch[d];
    k->ch[d]=t;
    t->Maintain();
    k->Maintain();
    t=k;
}

void Insert(Treap* &t,int x){
    if(t==NULL){
        t=new Treap(x);
    }else{
        int d=x < t->key ? 0:1;
        Insert(t->ch[d],x);
        if(t->ch[d]->pri > t->pri){
            Rotate(t,d^1);
	}
    }
    t->Maintain();
}

void Delete(Treap* &t,int x){
    int d=t->compare(x);
    if(d==-1){
        Treap *tmp=t;
        if(t->ch[0]==NULL){
            t=t->ch[1];
            delete tmp;
            tmp=NULL;
        }else if(t->ch[1]==NULL){
            t=t->ch[0];
            delete tmp;
            tmp=NULL;
        }else{
            int k=t->ch[0]->pri > t->ch[1]->pri ? 1:0;
            Rotate(t,k);
            Delete(t->ch[k],x);
        }
    }else{
        Delete(t->ch[d],x);
    }
    if(t!=NULL){
        t->Maintain();
    }
}

int Kth(Treap *t,int k){
    if(t==NULL||k<=0||k>t->size){
        return 0;
    }
    if(t->ch[0]==NULL&&k==1){
        return t->key;
    }
    if(t->ch[0]==NULL){
        return Kth(t->ch[1],k-1);
    }
    if(t->ch[0]->size>=k){
        return Kth(t->ch[0],k);
    }
    if(t->ch[0]->size+1==k){
        return t->key;
    }
    return Kth(t->ch[1],k-1-t->ch[0]->size);
}

void DeleteTreap(Treap* &t){//删除，释放内存
    if(t==NULL) return;
    if(t->ch[0]!=NULL){
        DeleteTreap(t->ch[0]);
    }
    if(t->ch[1]!=NULL){
        DeleteTreap(t->ch[1]);
    }
    delete t;
    t=NULL;
}

int n, m;
int g[100000][3];
stack<int> val[40000];
struct Ope{
	char t;
	int a, b;
	void init(char t1, int a1 = 0, int b1 = 0){
		t = t1;
		a = a1;
		b = b1;
	}
}op[1000000];

int fa[40000];
Treap* fax[40000];

void mergeTreap(Treap* &a, Treap* &b){
	if(a){
		if(a -> ch[0]){
			mergeTreap(a -> ch[0], b);
		}
		if(a -> ch[1]){
			mergeTreap(a -> ch[1], b);
		}
		Insert(b, a -> key);
		delete a;
		a = NULL;
	}
}

int uFind(int x){
    return (fa[x] == x) ? x : fa[x] = uFind(fa[x]);
}

void add(int u, int v){
    int fx = uFind(u);
    int fy = uFind(v);
    if(fx != fy){
        if(fax[fx] -> size < fax[fy] -> size){
            mergeTreap(fax[fx], fax[fy]);
            fa[fx] = fy;
        }else{
            mergeTreap(fax[fy], fax[fx]);
            fa[fy] = fx;
        }

    }
}

int main(){
    int cas = 0;
    while(~scanf("%d %d", &n, &m) && n || m){
    	for(int i = 1; i <= n; i++){
    		fa[i] = i;
    		fax[i] = NULL;
    		int tp;
    		scanf("%d", &tp);
    		tp = -tp;
    		while(!val[i].empty()){
                val[i].pop();
    		}
    		val[i].push(tp);
    	}
    	for(int i = 0; i < m; i++){
    		int u, v;
    		scanf("%d %d", &u, &v);
    		g[i][0] = u;
    		g[i][1] = v;
    		g[i][2] = 0;
    	}
    	char str[10];
    	int tot = 0;
    	while(~scanf("%s", str) && str[0] != 'E'){
    		int a, b;
    		if(str[0] == 'D'){
    			scanf("%d", &a);
    			a--;
    			g[a][2] = 1;
    		}else if(str[0] == 'C'){
    			scanf("%d %d", &a, &b);
    			b = -b;
    			val[a].push(b);
    		}else{
    			scanf("%d %d", &a, &b);
    		}
    		op[tot++].init(str[0], a, b);

    	}
    	for(int i = 1; i <= n; i++){
    		Insert(fax[i], val[i].top());
    	}
    	for(int i = 0; i < m; i++){
    		if(g[i][2] == 0){
    			add(g[i][0], g[i][1]);
    		}
    	}
    	int cnt = 0;
    	LL ans = 0;
    	while(tot--){
    		if(op[tot].t == 'C'){
    			int rt = uFind(op[tot].a);
    			Delete(fax[rt], val[op[tot].a].top());
    			val[op[tot].a].pop();

    			Insert(fax[rt], val[op[tot].a].top());

    		}else if(op[tot].t == 'D'){
    			int id = op[tot].a;
    			add(g[id][0], g[id][1]);
    		}else{
    			cnt++;
    			ans += Kth(fax[ uFind(op[tot].a) ], op[tot].b);
    		}
    	}
    	printf("Case %d: %.6f
", ++cas, (double)-ans / cnt);
    	for(int i = 1; i <= n; i++){
    		int fx = uFind(i);
    		if(fax[fx] != NULL){
    			DeleteTreap(fax[fx]);
    		}
    	}
    }

    return 0;
}

已经释放了内存，但在VS中使用_CrtDumpMemoryLeaks()函数检查还是有内存泄漏问题，原因还没弄清楚