cogs 1345 [ZJOI2013] K大数查询

---

【分析】

整体二分…好像是在CDQ的基础上再加一个二分QAQ
cogs评测机好快…刷到Rank1了…然而这题在bzoj上过不了(为啥数据不一样啊)，洛谷上会被卡一个比较奇葩的点…懵逼脸

---

【代码】

//K大数查询 #include<cstdio>#include<cstring>#include<iostream>#include<algorithm>#define ll long long#define M(a) memset(a,0,sizeof a)#define fo(i,j,k) for(i=j;i<=k;i++)using namespace std;const int mxn=50005;bool vis[mxn];int n,m,c1[mxn],c2[mxn],ans[mxn];struct query {int opt,l,r,v,id;} a[mxn],tmp[mxn];inline int lowbit(int x) {return x&-x;}inline void add_(int *c,int x,int v){    for(int i=x;i<=n;i+=lowbit(i))      c[i]+=v;}inline void add(int l,int r,int v){    add_(c1,l,v),add_(c1,r+1,-v);    add_(c2,l,v*(l-1)),add_(c2,r+1,-v*r);}inline int getsum(int *c,int x){    int S=0;    for(int i=x;i>=1;i-=lowbit(i))      S+=c[i];    return S;}inline int get(int l,int r){    int sum1=(l-1)*getsum(c1,l-1)-getsum(c2,l-1);    int sum2=r*getsum(c1,r)-getsum(c2,r);    return sum2-sum1;}inline void CDQ(int L,int R,int l,int r){    int i,j,mid=l+r>>1,l1=L,l2=R;    if(l==r)    {        fo(i,L,R) if(a[i].opt==2) ans[a[i].id]=l;        return;    }    fo(i,L,R)    {        if(a[i].opt==1)        {            if(a[i].v<=mid) tmp[l1++]=a[i];            else            {                add(a[i].l,a[i].r,1);                tmp[l2--]=a[i];            }        }        else        {            int cnt=get(a[i].l,a[i].r);            if(a[i].v>cnt)              a[i].v-=cnt,tmp[l1++]=a[i];            else tmp[l2--]=a[i];        }    }    reverse(tmp+l2+1,tmp+R+1);    fo(i,L,R) a[i]=tmp[i];    fo(i,L,R) if(a[i].opt==1 && a[i].v>mid) add(a[i].l,a[i].r,-1);    CDQ(L,l1-1,l,mid),CDQ(l2+1,R,mid+1,r);}int main(){    freopen("zjoi13_sequence.in","r",stdin);    freopen("zjoi13_sequence.out","w",stdout);    int i,j;    scanf("%d%d",&n,&m);    fo(i,1,m)    {        scanf("%d%d%d%d",&a[i].opt,&a[i].l,&a[i].r,&a[i].v);        if(a[i].opt==2) vis[i]=1;a[i].id=i;    }    CDQ(1,m,-n,n);    fo(i,1,m) if(vis[i]) printf("%d\n",ans[i]);    return 0;}