Submission #1110799

#	Time	Username	Problem	Language	Result	Execution time	Memory
1110799		whoknow	Index (COCI21_index)	C++17	60 / 110	223 ms	48200 KiB

index

#include <bits/stdc++.h>
#define ll long long
#define F first
#define S second
#define MAXN 200005
#define MAXTREE 3600005
#define ii pair<int,int>
#define bit(i,j) ((i>>j)&1)
#define sz(i) (int)i.size()
#define endl '\n'
using namespace std;
int n, ntest;
int a[MAXN];
namespace sub1
{
int node, MX;
int st[MAXTREE], root[MAXN];
ii child[MAXTREE];
void update(int id, int pre, int l, int r, int u)
{
    if(l == r)
        return st[id]=st[pre]+1, void();
    int mid = (l + r) / 2;
    node++;
    if(u <= mid)
    {
        child[id].F = node;
        child[id].S = child[pre].S;
        update(node, child[pre].F, l, mid, u);
    }
    else
    {
        child[id].F = child[pre].F;
        child[id].S = node;
        update(node, child[pre].S, mid + 1, r, u);
    }
    st[id] = st[child[id].F] + st[child[id].S];
}
int get(int id, int l, int r, int u, int v)
{
    if(l > v || r < u)
        return 0;
    if(l >= u && r <= v)
        return st[id];
    int mid = (l + r) / 2;
    return get(child[id].F, l, mid, u, v) + get(child[id].S, mid + 1, r, u, v);
}
int bina(int L, int R)
{
    int l = 1, r = R - L + 1;
    while(l < r)
    {
        int mid = (l + r+1) / 2;
        if(get(root[R], 1, MX, mid, MX) - get(root[L - 1], 1, MX, mid, MX) >= mid)
            l = mid;
        else
            r = mid - 1;
    }
    return l;
}
void solve()
{
    MX = *max_element(a + 1, a + 1 + n);
    for(int i = 1; i <= n; i++)
    {
        node++;
        root[i] = node;
        update(node, root[i - 1], 1, MX, a[i]);
    }
//    cout << get(root[n], 1, MX, 1, MX) << endl;
    for(int i = 1; i <= ntest; i++)
    {
        int l, r;
        cin >> l >> r;
        cout << bina(l, r) << endl;
    }
}
}
main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cin >> n >> ntest;
    for(int i = 1; i <= n; i++)
        cin >> a[i];
    sub1::solve();
}

Compilation message (stderr)

index.cpp:79:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   79 | main()
      | ^~~~

• Subtask 1: 20 / 20
• Subtask 2: 40 / 40
• Subtask 3: 0 / 50