Submission #891847

#	Time	Username	Problem	Language	Result	Execution time	Memory
891847		12345678	Bridges (APIO19_bridges)	C++17	0 / 100	259 ms	1872 KiB

bridges

#include <bits/stdc++.h>

using namespace std;

const int nx=5e4+5;
int n, m, q, w[nx], u[nx], v[nx], t, idx, vl, st, k;

struct segtree
{
    int d[4*nx];
    void build(int l, int r, int i)
    {
        if (l==r) return void(d[i]=w[l]);
        int md=(l+r)/2;
        build(l, md, 2*i);
        build(md+1, r, 2*i+1);
        d[i]=max(d[2*i], d[2*i+1]);
    }
    void update(int l, int r, int i, int idx, int vl)
    {
        if (idx<l||r<idx) return;
        if (l==r) return void(d[i]=vl);
        int md=(l+r)/2;
        update(l, md, 2*i, idx, vl);
        update(md+1, r, 2*i+1, idx, vl);
        d[i]=max(d[2*i], d[2*i+1]);
    }
    int query(int l, int r, int i, int ql, int qr)
    {
        //cout<<"query "<<l<<' '<<r<<' '<<ql<<' '<<qr<<'\n';
        if (qr<l||r<ql) return INT_MIN;
        if (ql<=l&&r<=qr) return d[i];
        int md=(l+r)/2;
        return max(query(l, md, 2*i, ql, qr), query(md+1, r, 2*i+1, ql, qr));
    }
} s;

int main()
{
    cin.tie(NULL)->sync_with_stdio(false);
    cin>>n>>m;
    for (int i=1; i<n; i++) cin>>u[i]>>v[i]>>w[i];
    cin>>q;
    s.build(1, n-1, 1);
    //for (int i=1; i<n; i++) for (int j=i; j<n; j++) cout<<i<<' '<<j<<' '<<s.query(1, n-1, 1, i, j)<<'\n';
    while (q--)
    {
        cin>>t;
        if (t==1) cin>>idx>>vl, s.update(1, n-1, 1, idx, vl);
        else
        {
            cin>>st>>k;
            int l=1, r=st;
            while (l<r)
            {
                int md=(l+r)/2;
                if (s.query(1, n-1, 1, md, st-1)<=k) r=md;
                else l=md+1;
            }
            //if (st==1||s.query(1, n-1, 1, st-1, st-1)>k) l=st;
            int l2=st, r2=n-1;
            while (l2<r2)
            {
                int md=(l2+r2+1)/2;
                if (s.query(1, n-1, 1, st, md)<=k) l2=md;
                else r2=md-1;
            }
            if (st==n||s.query(1, n-1, 1, st, st)>k) l2=st-1;
            cout<<(l2-l+2)<<'\n';
        }
    }
}

/*
5 4
1 2 5
2 3 3
3 4 10
4 5 1
10
2 1 6
2 2 6
2 2 4
2 5 11
2 4 2
2 1 20
2 1 0
2 5 10
2 5 2
2 5 0
*/

• Subtask 1: 0 / 13
• Subtask 2: 0 / 16
• Subtask 3: 0 / 17
• Subtask 4: 0 / 14
• Subtask 5: 0 / 13
• Subtask 6: 0 / 27