ZOJ2112(区间动态求第K大)

题目：Dynamic Rankings

 

题意：

N<=50000 M<=10000，给定一个数组A[1]~A[N]，有M个操作

每个操作可以如下

Q i j t 输出 A[I]~A[J]之间第t小的数

C i t 将A[I]赋值为t

#include <cstdio>#include <cstring>#include <cstdlib>#include <iostream>#include <algorithm>using namespace std;#define N 60010#define M 10010#define INF 1000000000char ctrl[M][3];int cnt,n,m;int P[M],Q[M],a[N],b[N],K[M];struct treap{   int key,wei,cnt,size,ch[2];}T[N * 15];int tree[N << 1],nodecnt,root;void init(){   T[0].size = 0;   T[0].wei = -INF;   nodecnt = root = 0;}int ID(int l,int r){    return l + r | l != r;}void update(int x){   T[x].size = T[T[x].ch[0]].size + T[T[x].ch[1]].size + T[x].cnt;}void rotate(int &x,int t){   int y = T[x].ch[t];   T[x].ch[t] = T[y].ch[!t];   T[y].ch[!t] = x;   update(x);   update(y);   x = y;}void insert(int &x,int t){   if (!x)   {       x = ++ nodecnt;       T[x].key = t;       T[x].wei = rand();       T[x].cnt = 1;       T[x].ch[0] = T[x].ch[1] = 0;   }   else if (T[x].key == t)       T[x].cnt ++;   else   {       int k = T[x].key < t;       insert(T[x].ch[k],t);       if (T[x].wei < T[T[x].ch[k]].wei)           rotate(x,k);   }   update(x);}void erase(int &x,int t){   if (T[x].key == t)   {       if (T[x].cnt == 1)       {           if (!T[x].ch[0] && !T[x].ch[1])           {               x = 0;               return;           }           rotate(x,T[T[x].ch[0]].wei < T[T[x].ch[1]].wei);           erase(x,t);       }       else T[x].cnt--;   }   else       erase(T[x].ch[T[x].key < t],t);   update(x);}int select(int x,int t){   if (!x) return 0;   if (T[x].key > t) return select(T[x].ch[0],t);   return T[x].cnt + T[T[x].ch[0]].size + select(T[x].ch[1],t);}void treeins(int l,int r,int i,int x){   insert(tree[ID(l,r)],x);   if (l == r) return;   int m = l + r >> 1;   if (i <= m) treeins(l,m,i,x);   else treeins(m + 1,r,i,x);}void treedel(int l,int r,int i,int x){   erase(tree[ID(l,r)],x);   if (l == r) return;   int m = l + r >> 1;   if (i <= m) treedel(l,m,i,x);   else treedel(m + 1,r,i,x);}int query(int l,int r,int x,int y,int t){   if (l == r) return l;   int m = l + r >> 1;   int ans = select(tree[ID(l,m)],y) - select(tree[ID(l,m)],x);   if (ans >= t) return query(l,m,x,y,t);   return query(m + 1,r,x,y,t - ans);}int main(){   int Times;   scanf("%d",&Times);   while (Times --)   {       scanf("%d%d",&n,&m);       memset(tree,0,sizeof tree);       init();       cnt = 0;       for (int i = 1;i <= n;i ++)           scanf("%d",&a[i]),b[++ cnt] = a[i];       for (int i = 1;i <= m;i ++)       {           scanf("%s%d%d",ctrl[i],&P[i],&Q[i]);           if (ctrl[i][0] == 'Q')               scanf("%d",&K[i]);           else               b[++ cnt] = Q[i];       }       sort(b + 1,b + 1 + cnt);       cnt = unique(b + 1,b + 1 + cnt) - b - 1;       for (int i = 1;i <= n;i ++)       {           a[i] = lower_bound(b + 1,b + 1 + cnt,a[i]) - b;           treeins(1,cnt,a[i],i);       }       for(int i = 1;i <= m;i ++)       {           if (ctrl[i][0] == 'Q')           {               int id = query(1,cnt,P[i] - 1,Q[i],K[i]);               printf("%d\n",b[id]);           }           else           {               treedel(1,cnt,a[P[i]],P[i]);               a[P[i]] = lower_bound(b + 1,b + 1 + cnt,Q[i]) - b;               treeins(1,cnt,a[P[i]],P[i]);           }       }   }   return 0;}