4721. 排队

树状数组 + 离散化

#include 
#include 
#include 
#include 

using namespace std;

const int N = 1e5 + 10;

int n;

int tr[N], a[N];
vector<int> alls;
int res[N];

int lowbit(int x)
{
    return x & -x;
}

void add(int x, int c)
{
    for(int i = x; i <= n; i += lowbit(i))
        tr[i] = max(tr[i], c);
}

int query(int x)
{
    int res = 0;
    for(int i = x; i; i -= lowbit(i))
        res = max(res, tr[i]);
    return res;
}

int find(int x)
{
    int l = 0, r = alls.size() - 1;
    while(l < r)
    {
        int mid = (l + r + 1) >> 1;
        if(alls[mid] <= x)
            l = mid;
        else
            r = mid - 1;
    }
    return r + 1;
}


int main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    
    cin >> n;
    for(int i = 1; i <= n; i ++)
    {
        cin >> a[i];
        alls.push_back(a[i]);
    }
    
    sort(alls.begin(), alls.end());
    alls.erase(unique(alls.begin(), alls.end()), alls.end());
    
    for(int i = n; i ;i --)
    {
        int x = find(a[i]);
        add(x, i);
        int t = query(x - 1);
        
        if(t <= i) res[i] = -1;
        else res[i] = t - i - 1;
    }
    
    for(int i = 1; i <= n; i ++)
        cout << res[i] << " ";
    cout << endl;
    return 0;
}
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