제출 #805202

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
805202		vjudge1	Index (COCI21_index)	C++17	110 / 110	1274 ms	56144 KiB

index

#include <bits/stdc++.h>
using namespace std;

const int maxn=2e5+5;
int n, q, cnt=1, mx=0;
int ver[maxn];
struct T
{
    int x, no;
} a[maxn];
struct Node
{
    int l, r, v;
    Node() {};
    Node(int x, int y, int z)
    {
        l=x; r=y; v=z;
    }
} d[22*maxn];

bool lf(const T& i, const T& j)
{
    return i.x>j.x;
}

void build(int i, int l, int r)
{
    if (l==r) return;
    d[i].l=++cnt; d[i].r=++cnt;
    int mid=(l+r)/2;
    build(d[i].l, l, mid);
    build(d[i].r, mid+1, r);
}

int update(int i, int l, int r, int x)
{
    int cur=++cnt;
    if (l==r)
    {
        d[cur]=Node(0,0,1);
        return cur;
    }
    d[cur]=d[i];
    int mid=(l+r)/2;
    if (x<=mid) d[cur].l=update(d[i].l, l, mid, x);
    else d[cur].r=update(d[i].r, mid+1, r, x);
    d[cur].v=d[d[cur].l].v+d[d[cur].r].v;
    return cur;
}

int get(int i, int l, int r, int x, int y)
{
    if (r<x || l>y) return 0;
    if (x<=l && r<=y) return d[i].v;
    int mid=(l+r)/2;
    return get(d[i].l, l, mid, x, y)+get(d[i].r, mid+1, r, x, y);
}

int ssearch(int x)
{
    int l=1, r=n;
    while (l<=r)
    {
        int mid=(l+r)/2;
        if (a[mid].x>=x) l=mid+1;
        else r=mid-1;
    }
    return r;
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cin >> n >> q;
    for (int i=1; i<=n; ++i)
    {
        cin >> a[i].x;
        a[i].no=i;
        mx=max(a[i].x, mx);
    }
    sort(a+1, a+n+1, lf);
    build(1, 1, n);
    ver[0]=1;
    for (int i=1; i<=n; ++i)
        ver[i]=update(ver[i-1], 1, n, a[i].no);
    int x, y;
    while (q--)
    {
        cin >> x >> y;
        int l=1, r=mx;
        while (l<=r)
        {
            int mid=(l+r)/2;
            int s=ssearch(mid);
            if (get(ver[s], 1, n, x, y)>=mid)
                l=mid+1;
            else r=mid-1;
        }
        cout << r << '\n';
    }
}

• Subtask 1: 20 / 20
• Subtask 2: 40 / 40
• Subtask 3: 50 / 50