BZOJ 1901 Dynamic Rankings

数据结构模版题【连这么神的题都沦为模版题了Orz

对数离散化后树状数组套权值线段树。

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#include <cstdlib>

#include <cstdio>

#include <cctype>

#include <cstring>

#include <cmath>

#include <iostream>

#include <algorithm>

#define rep(i, l, r) for(int i=l; i<=r; i++)

#define clr(x, c) memset(x, c, sizeof(x))

#define lowbit(x) (x&-x)

#define maxn 10009

#define maxm 20009

#define inf 0x7fffffff

#define k(x) Key[x]

#define t(x) Tree[x]

using namespace std;

inline int read()

{

    int x=0, f=1; char ch=getchar();

    while (!isdigit(ch)) {if (ch=='-') f=-1; ch=getchar();}

    while (isdigit(ch)) x=x*10+ch-'0', ch=getchar();

    return x*f;

}

struct node{node *l, *r; int sum;} *blank=new(node), *Tree[maxn], *r1[maxn], *r2[maxn];

struct node2{int v, n;} num[maxm];

bool cmp(node2 a, node2 b){return a.v<b.v;}

int n, m, V, q[maxn][4], Key[maxm], ln, n1, n2, c[maxm];

char ch[5];

void Build(int l, int r, node*&t)

{

    if (t==blank) t=new(node), t->l=t->r=blank, t->sum=0;

    if (l==r) return;

    int mid=(l+r)>>1;

    Build(l, mid, t->l), Build(mid+1, r, t->r);

}

void Add(int k, int y, int l, int r, node *u, node*&t)

{

    if (t==blank) t=new(node), t->l=t->r=blank, t->sum=0;

    t->sum=u->sum+y;

    if (l==r) return; int mid=(l+r)>>1;

    if (k<=mid)

        t->r=u->r, Add(k, y, l, mid, u->l, t->l);

    else

        t->l=u->l, Add(k, y, mid+1, r, u->r, t->r);

}

inline void Change(int t, int k)

{

    node *p; int v=k(t); k(t)=k;

    for(int x=t; x<=n; x+=lowbit(x))

        Add(v, -1, 1, ln, t(x), p=blank), t(x)=p;

    for(int x=t; x<=n; x+=lowbit(x))

        Add(k, 1, 1, ln, t(x), p=blank), t(x)=p;

}

inline int Query(int l, int r, int k)

{

    n1=n2=0; k--;

    for(int x=l-1; x; x-=lowbit(x)) r1[++n1]=t(x);

    for(int x=r; x; x-=lowbit(x)) r2[++n2]=t(x);

    int L=1, R=ln;

    while (L<R)

    {

        int sum=0, mid=(L+R)>>1;

        rep(j, 1, n1) sum-=r1[j]->l->sum;

        rep(j, 1, n2) sum+=r2[j]->l->sum;

        if (sum<=k)

        {

            L=mid+1, k-=sum;

            rep(j, 1, n1) r1[j]=r1[j]->r;

            rep(j, 1, n2) r2[j]=r2[j]->r;

        }

        else

        {

            R=mid;

            rep(j, 1, n1) r1[j]=r1[j]->l;

            rep(j, 1, n2) r2[j]=r2[j]->l;

        }

    }

    return c[L];

}

void Init(){blank->l=blank->r=blank; blank->sum=0;}

int main()

{

    n=V=read(), m=read(); Init();

    rep(i, 1, n) num[i].v=read(), num[i].n=i;

    rep(i, 1, m)

    {

        scanf("%s", ch);

        if (ch[0]=='Q')

            q[i][0]=1, q[i][1]=read(), q[i][2]=read(), q[i][3]=read();

        else

        {

            q[i][0]=0, q[i][1]=read(), q[i][2]=read();

            ++V, num[V].v=q[i][2], num[V].n=n+i;

        }

    }

    sort(num+1, num+V+1, cmp);

    c[++ln]=num[1].v, k(num[1].n)=1;

    rep(i, 2, V)

    {

        if (num[i].v != num[i-1].v) c[++ln]=num[i].v;

        k(num[i].n)=ln;

    }

    Build(1, ln, t(0)=blank);

    rep(i, 1, n)

    {

        node *p=t(0);

        rep(j, i-lowbit(i)+1, i)

            Add(k(j), 1, 1, ln, p, t(i)=blank), p=t(i);

    }

    rep(i, 1, m)

        if (!q[i][0]) Change(q[i][1], k(n+i));

        else printf("%d\n", Query(q[i][1], q[i][2], q[i][3]));

    return 0;

}