Dynamic Rankings（zoj 2112）

题意：带修改的第K大

#include<cstdio>
#include<iostream>
#include<cstring>
#define N 400010
#define inf 1000000000
using namespace std;
int a[N],ans[N],sum[N],tmp[N],n,m,num,cnt;
struct node{
    int x,y,s,k,tp,cur;
};node q[N],q1[N],q2[N];
void modify(int x,int v){
    while(x<=n){
        sum[x]+=v;
        x+=x&(-x);
    }
}
int query(int x){
    int tot=0;
    while(x){
        tot+=sum[x];
        x-=x&(-x);
    }
    return tot;
}
void solve(int head,int tail,int l,int r){
    if(head>tail)return;
    if(l==r){
        for(int i=head;i<=tail;i++)
            if(q[i].tp==3)ans[q[i].s]=l;
        return;
    }
    int mid=l+r>>1;
    for(int i=head;i<=tail;i++){
        if(q[i].tp==1&&q[i].y<=mid)modify(q[i].x,1);
        if(q[i].tp==2&&q[i].y<=mid)modify(q[i].x,-1);
        if(q[i].tp==3) tmp[i]=query(q[i].y)-query(q[i].x-1);
    }
    for(int i=head;i<=tail;i++){
        if(q[i].tp==1&&q[i].y<=mid)modify(q[i].x,-1);
        if(q[i].tp==2&&q[i].y<=mid)modify(q[i].x,1);
    }
    int l1=0,l2=0;
    for(int i=head;i<=tail;i++){
        if(q[i].tp==3){
            if(q[i].cur+tmp[i]>=q[i].k) q1[++l1]=q[i];
            else q[i].cur+=tmp[i],q2[++l2]=q[i];
        }
        else {
            if(q[i].y<=mid) q1[++l1]=q[i];
            else q2[++l2]=q[i];
        }
    }
    for(int i=1;i<=l1;i++) q[head+i-1]=q1[i];
    for(int i=1;i<=l2;i++) q[head+l1+i-1]=q2[i];
    solve(head,head+l1-1,l,mid);
    solve(head+l1,tail,mid+1,r);
}
void work(){
    for(int i=1;i<=n;i++){
        scanf("%d",&a[i]);
        q[++num].x=i;q[num].y=a[i];q[num].tp=1;q[num].s=0;
    }
    scanf("%d",&m);
    for(int i=1;i<=m;i++){
        int op;scanf("%d",&op);
        if(op==1){
            int x,y;scanf("%d%d",&x,&y);
            q[++num].x=x;q[num].y=a[x];q[num].tp=2;q[num].s=0;
            q[++num].x=x;q[num].y=y;q[num].tp=1;q[num].s=0;
            a[x]=y;
        }
        else {
            int x,y,k;scanf("%d%d%d",&x,&y,&k);
            q[++num].x=x;q[num].y=y;q[num].k=k;q[num].tp=3;q[num].s=++cnt;
        }
    }
    solve(1,num,-inf,inf);
    for(int i=1;i<=cnt;i++)
        printf("%d
",ans[i]);
}
int main(){
    while(scanf("%d",&n)!=EOF){
        memset(ans,0,sizeof(ans));
        memset(tmp,0,sizeof(tmp));
        memset(sum,0,sizeof(sum));
        memset(q,0,sizeof(q));
        num=cnt=0;
        work();
    }
    return 0;
}