Create 1034_pawa-luodi.cpp

From https://vijos.org/p/1081/solution

QUSTOJ/1034_pawa-luodi.cpp

@@ -0,0 +1,133 @@
+#include <cstdio>
+#include <cstring>
+#include <iostream>
+#include <algorithm>
+#define MAX 100010
+#define _MAX 50010
+using namespace std;
+
+struct ComplexAsk{
+    int l,r,k;
+    int from;
+    bool operator <(const ComplexAsk& a)const{
+        return l<a.l;
+    } 
+}asks[_MAX];
+struct Complex{
+    int random,val,cnt,size;
+    Complex* son[2];
+    Complex(){
+        random=rand();
+        cnt=size=1;
+        son[0]=son[1]=NULL;
+    }
+    inline void Maintain(){
+        size=cnt;
+        if(son[0]!=NULL)    size+=son[0]->size;
+        if(son[1]!=NULL)    size+=son[1]->size;
+    }
+    inline int Compare(int x){
+        if(x==val)  return -1;
+        return x>val;
+    }
+}*root;
+
+int total,step;
+int source[MAX];
+int ans[_MAX];
+
+inline void Rotate(Complex*& a,int dir);
+void Insert(Complex*& a,int x);
+void Delete(Complex*& a,int x);
+int FindK(Complex*& a,int k);
+
+int main()
+{
+    cin>>total>>step;
+    for(int i=1;i<=total;i++)
+        scanf("%d",&source[i]);
+    for(int i=1;i<=step;i++)
+        scanf("%d%d%d",&asks[i].l,&asks[i].r,&asks[i].k),asks[i].from=i;
+    sort(asks+1,asks+step+1);
+    for(int i=1;i<=step;i++){
+        if(asks[i-1].r>=asks[i].l){
+            for(int j=asks[i-1].l;j<asks[i].l;j++)
+                Delete(root,source[j]);
+            for(int j=asks[i-1].r+1;j<=asks[i].r;j++)
+                Insert(root,source[j]);
+        }
+        else{
+            if(i-1)
+                for(int j=asks[i-1].l;j<=asks[i-1].r;j++)
+                    Delete(root,source[j]);
+            for(int j=asks[i].l;j<=asks[i].r;j++)
+                Insert(root,source[j]);
+        }
+        ans[asks[i].from]=FindK(root,asks[i].k);
+    }
+    for(int i=1;i<=step;i++)
+        printf("%d\n",ans[i]);
+    return 0;
+}
+
+inline void Rotate(Complex*& a,int dir)
+{
+    Complex* k=a->son[dir^1];
+    a->son[dir^1]=k->son[dir];
+    k->son[dir]=a;
+    a->Maintain(),k->Maintain();
+    a=k;
+}
+
+void Insert(Complex*& a,int x)
+{
+    if(a==NULL){
+        a=new Complex();
+        a->val=x;
+        return ;
+    }
+    int dir=a->Compare(x);
+    if(dir==-1)
+        a->cnt++;
+    else{
+        Insert(a->son[dir],x);
+        if(a->son[dir]->random > a->random)
+            Rotate(a,dir^1);
+    }
+    a->Maintain();
+}
+
+void Delete(Complex*& a,int x)
+{
+    int dir=a->Compare(x);
+    if(dir!=-1)
+        Delete(a->son[dir],x);
+    else{
+        if(a->cnt > 1)
+            a->cnt--;
+        else{
+            if(a->son[0]==NULL)
+                a=a->son[1];
+            else if(a->son[1]==NULL)
+                a=a->son[0];
+            else{
+                int _dir=(a->son[0]->random > a->son[1]->random);
+                Rotate(a,_dir);
+                Delete(a->son[_dir],x);
+            }
+        }
+    }
+    if(a!=NULL) a->Maintain();
+}
+
+int FindK(Complex*& a,int k)
+{
+    int t=0;
+    if(a->son[0]!=NULL)
+        t=a->son[0]->size;
+    if(k<=t)
+        return FindK(a->son[0],k);
+    if(k>t+a->cnt)
+        return FindK(a->son[1],k-t-a->cnt);
+    return a->val;
+}