Bzoj 1901: zju2112 dynamic rankings (decision tree)

1901: zju2112 dynamic rankings

Classic question about the minimum K value of the interval with Modification

Tree Cover tree templates are implemented by using the splay of Line Segment trees and simulating them using arrays. Therefore, the space may be slightly larger. bzoj has passed, and zoj has not passed.

The idea is very simple. Use a line segment tree to maintain the interval, use splay to maintain the weights in the interval, and then use the binary answer key to find the number of keys smaller than the number of keys in the interval.

Paste template:

#include<stdio.h>#include<string.h>#include<algorithm>#define lson l , m , rt<<1#define rson m + 1 , r , rt<<1|1#define ls son[0][rt]#define rs son[1][rt]using namespace std ; const int maxn = 100001 ;const int N = maxn*18 ;const int INF = 1111111111 ;int a[maxn] , n , pool[N] , top ;struct TTT {    int son[2][N] , size[N] , fa[N] , val[N] ;    int root[N] , tot ;    void push_up ( int rt ) {        size[rt] = size[ls] + size[rs] + 1 ;    }    int new_node ( int _val ) {        int rt ;        if ( top ) rt = pool[top--] ;        else rt = ++tot ;        size[rt] = 1 ;        ls = rs = fa[rt] = 0 ;        val[rt] = _val ;        return rt ;    }    void build_root ( int rt ) {        rs = new_node ( INF ) ;        fa[rs] = rt ;    }    void build ( int l , int r , int rt ) {        root[rt] = new_node(-INF) ;        build_root ( root[rt] ) ;        if ( l == r ) return ;        int m = l + r >> 1 ;        build ( lson ) ;        build ( rson ) ;    }    void rot ( int rt ) {        int y = fa[rt] , z = fa[y] , c = rt == son[0][y] ;        son[!c][y] = son[c][rt] , fa[son[c][rt]] = y ;        son[c][rt] = y , fa[y] = rt ;        fa[rt] = z ;        son[y==son[1][z]][z] = rt ;        push_up ( y ) ;    }    void splay ( int rt , int to ) {        while ( fa[rt] != to ) {            int y = fa[rt] , z = fa[y] ;            if ( z != to ) rot ( (rt==son[0][y])^(y==son[0][z]) ? rt : y ) ;            rot ( rt ) ;        }        push_up ( rt ) ;    }    int find_smaller ( int rt , int v ) {        int ret ;        if ( val[rt] >= v ) {            if ( !ls ) return rt ;            ret = find_smaller ( ls , v ) ;        } else {            if ( !rs ) return rt ;            ret = find_smaller ( rs , v ) ;            if ( val[ret] >= v ) ret = rt ;        }        return ret ;    }    int find_left_most ( int rt ) {        while ( ls ) rt = ls ;        return rt ;    }    int count_smaller ( int rt , int v ) {        if ( !rt ) return 0 ;        if ( val[rt] < v ) return size[ls] + 1 + count_smaller ( rs , v ) ;        else return count_smaller ( ls , v ) ;    }    void add ( int& rt , int v ) {        rt = find_smaller ( rt , v ) ;        splay ( rt , 0 ) ;        int temp = find_left_most ( rs ) ;        splay ( temp , rt ) ;        son[0][temp] = new_node ( v ) ;        fa[son[0][temp]] = temp ;        push_up ( temp ) ; push_up ( rt ) ;    }    void print ( int rt ) {        if ( !rt ) return ;        printf ( "rt = %d , sz = %d\n" , rt , size[rt] ) ;        printf ( "ls = %d , rs = %d , fa = %d , val = %d\n" , ls , rs , fa[rt] , val[rt] ) ;        print ( ls ) ;        print ( rs ) ;    }    void del ( int& rt , int v ) {        rt = find_smaller ( rt , v ) ;        splay ( rt , 0 ) ;        int temp = find_left_most ( rs ) ;        if ( val[temp] != v ) return ;        splay ( temp , rt ) ;        temp = find_left_most ( son[1][temp] ) ;        splay ( temp , rt ) ;        pool[++top] = son[0][temp] ;        son[0][temp] = 0 ;        push_up ( temp ) ; push_up ( rt ) ;    }    void update ( int pos , int v , int op , int l , int r , int rt ) {        if ( op == 0 ) {            add ( root[rt] , v ) ;        }        else del ( root[rt] , v ) ;        if ( l == r ) return ;        int m = l + r >> 1 ;        if ( pos <= m ) update ( pos , v , op , lson ) ;        else update ( pos , v , op , rson ) ;    }    int count ( int a , int b , int v , int l , int r , int rt ) {        if ( a <= l && r <= b ) {            int k = count_smaller ( root[rt] , v ) - 1 ;            return k ;        }        int m = l + r >> 1 , ret = 0 ;        if ( a <= m ) ret = count ( a , b , v , lson ) ;        if ( m < b ) ret += count ( a , b , v , rson ) ;        return ret ;    }    void init () {        tot = 0 ;        top = 0 ;        build ( 1 , n , 1 ) ;        for ( int i = 1 ; i <= n ; i ++ ) {    //      printf ( "a[%d] = %d\n" , i , a[i] ) ;            update ( i , a[i] , 0 , 1 , n , 1 ) ;        }    }    int ask ( int a , int b , int k ) {        int l = 0 , r = 1000000000 ;        while ( l <= r ) {            int m = l + r >> 1 ;            int cnt = count ( a , b , m , 1 , n , 1 ) ;//          printf ( "m = %d , cnt = %d\n" , m , cnt ) ;            if ( cnt <= k - 1 ) l = m + 1 ;            else r = m - 1 ;//          printf ( "l = %d , r = %d\n" , l , r ) ;        }        return r ;    }    void modify ( int pos , int num ) {        update ( pos , a[pos] , 1 , 1 , n , 1 ) ;        update ( pos , num , 0 , 1 , n , 1 ) ;        a[pos] = num ;    }} ttt ;int main () {    int T , m ;//  freopen ( "a.in" , "r" , stdin ) ;//  scanf ( "%d" , &T ) ;    while ( scanf ( "%d%d" , &n , &m ) != EOF ) {        for ( int i = 1 ; i <= n ; i ++ )            scanf ( "%d" , &a[i] ) ;        ttt.init () ;        while ( m -- ) {            char op[11] ;            int x , y , z ;            scanf ( "%s" , op ) ;            if ( op[0] == 'Q' ) {                scanf ( "%d%d%d" , &x , &y , &z ) ;                printf ( "%d\n" , ttt.ask ( x , y , z ) ) ;            } else {                scanf ( "%d%d" , &x , &y ) ;                ttt.modify ( x , y ) ;            }        }    }    return 0 ;}

Bzoj 1901: zju2112 dynamic rankings (decision tree)