营业额统计

传送门
这个题...裸题啊,裸的不能再裸了

按天数插入,每次插入之后,比较和前驱后继的差,取 min 统计入答案即可

注意之前已经插入过的值就不需要插入了.然后这题就 A 了

Code:

#include <iostream>
#include <cstdlib>
#include <cstdio>
#include <ctime>
#include <cmath>
#include <map>
#define Drt pair < Treap * , Treap * >
#define siz(rt) ( rt == NULL ? 0 : rt->size )

using std::pair ;
using std::map ;

const int INF = 1061109567 ;
map < int , bool > mk ;
int n , ans , xx ;

struct Treap {
    Treap * son[2] ;
    int val , size , rank ;
    Treap ( int val ) : val ( val ) { son[0] = son[1] = NULL ; size = 1 ; rank = rand () ; }
    inline void maintain () {
        this->size = 1 ;
        if ( this->son[0] != NULL ) this->size += this->son[0]->size ;
        if ( this->son[1] != NULL ) this->size += this->son[1]->size ;
        return ;
    }
} * root = NULL ;

inline Drt Split ( Treap * rt , int k ) {
    if ( rt == NULL ) return Drt ( NULL , NULL ) ;
    Drt t ;
    if ( k <= siz ( rt->son[0] ) ) {
        t = Split ( rt->son[0] , k ) ; rt->son[0] = t.second ;
        rt->maintain () ; t.second = rt ;
    } else {
        t = Split ( rt->son[1] , k - siz ( rt->son[0] ) - 1 ) ;
        rt->son[1] = t.first ; rt->maintain () ; t.first = rt ;
    }
    return t ;
}

inline Treap * merge ( Treap * x , Treap * y ) {
    if ( x == NULL ) return y ; if ( y == NULL ) return x ;
    if ( x->rank < y->rank ) {
        x->son[1] = merge ( x->son[1] , y ) ;
        x->maintain () ; return x ;
    } else {
        y->son[0] = merge ( x , y->son[0] ) ;
        y->maintain () ; return y ;
    }
}

inline int Getrank ( Treap * rt , int key ) {
    if ( rt == NULL ) return 0 ;
    if ( key <= rt->val ) return Getrank ( rt->son[0] , key ) ;
    else return Getrank ( rt->son[1] , key ) + siz ( rt->son[0] ) + 1 ;
}

inline int Getkth ( Treap * & rt , int key ) {
    Drt x = Split ( rt , key - 1 ) ;
    Drt y = Split ( x.second , 1 ) ;
    Treap * node = y.first ;
    rt = merge ( x.first , merge ( node , y.second ) ) ;
    return node == NULL ? 0 : node->val ;
}

inline void insert ( Treap * & rt , int key ) {
    int k = Getrank ( rt , key ) ; Drt t = Split ( rt , k ) ;
    Treap * node = new Treap ( key ) ;
    rt = merge ( t.first , merge ( node , t.second ) ) ;
    return ;
}

int main () {
    scanf ("%d" , & n ) ; scanf ("%d" , & xx ) ; n -- ;
    ans = xx ; mk[xx] = true ; insert ( root , xx ) ;
    while ( n -- ) {
        scanf ("%d" , & xx ) ;
        if ( mk[xx] ) continue ; mk[xx] = true ; insert ( root , xx ) ;
        int a = abs ( Getkth ( root , Getrank ( root , xx ) ) - xx ) ;
        int b = abs ( Getkth ( root , Getrank ( root , xx + 1 ) + 1 ) - xx ) ;
        if ( a == 0 ) a = INF ; if ( b == 0 ) b = INF ;
        ans += std::min ( a , b ) ;
    }
    printf ("%d
" , ans ) ; system ("pause") ; return 0 ;
}