Luo Gu P1110 [ZJOI2007] report statistics

Luoguziti

Luo Gu P1110 [ZJOI2007] report statistics

First, understanding the problem: we are nothing more than put this sequence into n sections, insert a new element at the end of each period. ( I think it is very simple na )

This problem no handwriting balanced tree, do not heap, with only two arrays, two multiset and a variable like ......

Let's maintain two arrays, st [] and ed [] represents an element of the elements and at the end of each section beginning.

Let us maintain two multiset <int>, a man named full, represent all elements (existing value). Another called delta, represents all the difference.

Then almost ......

On the code:

#include<cstdio>
#include<set>
#include<cstdlib>
#include<cctype>
using namespace std;
const int maxn=5e5+1e2;
const int inf=0x3f3f3f3f;

multiset<int> delta,full;
int st[maxn],ed[maxn];
int srt=inf;
int n,m;

inline void update_srt(int x)
{
    multiset<int>::iterator it = full.lower_bound(x);
    int nw = *it - x;
    --it;
    nw = min( nw , x - *it );
    srt = min( srt , nw );
    full.insert(x);
}

inline void replac(int pos,int x)
{
    delta.insert( abs( x - ed[pos] ) );
    if( pos != n )
        delta.erase( delta.find( abs( st[pos+1] - ed[pos] ) ) ),
        delta.insert( abs( st[pos+1] - x ) );
    ed[pos] = x;
}

inline int getint()
{
    int ret = 0 , fix = 1;
    char ch = getchar();
    while( !isdigit(ch) )
    {
        if( ch == '-' )
            fix = -1;
        ch = getchar();
    }
    while( isdigit(ch) )
        ret = ret * 10 + ( ch - '0' ),
        ch = getchar();
    return ret * fix;
}

int main()
{
    static char str[1<<5];
    n = getint() , m = getint();
    for(int i=1;i<=n;i++)
        st[i] = ed[i] = getint();

    full.insert(inf),
    full.insert(-inf);
    for(int i=1;i<n;i++)
        delta.insert( abs( st[i+1] - ed[i] ) );
    for(int i=1;i<=n;i++)
        update_srt(st[i]);
    for(int i=1,pos,x;i<=m;i++)
    {
        scanf("%s",str);
        if( *str == 'I' )
        {
            pos = getint() , x = getint();
            update_srt(x);
            replac(pos,x);
        }
        else if( str[4] == 'S' )
            printf("%d\n",srt);
        else
            printf("%d\n",*delta.begin());
    }
    return 0;
}