Submission #772377

#	Time	Username	Problem	Language	Result	Execution time	Memory
772377		phoebe	Bridges (APIO19_bridges)	C++17	0 / 100	734 ms	6232 KiB

bridges

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

#define int long long
#define ll long long
#define pii pair<int, int>
#define F first
#define S second
#define FOR(i, n) for (int i = 0; i < n; i++)
#define PB push_back
#define ALL(x) x.begin(), x.end()
#define NYOOM ios::sync_with_stdio(0); cin.tie(0);
const int INF = 1e9 + 7;

// solving ST 4: offline query 

const int maxn = 1e5 + 10;
int n, m, u[maxn], v[maxn], d[maxn], q, tree[maxn * 4];

void update(int x, int v, int tl = 0, int tr = maxn, int i = 1){
    if (tl > x || tr < x) return;
    if (tl == tr){
        tree[i] = v; return;
    }
    int tm = (tl + tr) / 2;
    update(x, v, tl, tm, i * 2); update(x, v, tm + 1, tr, i * 2 + 1);
    tree[i] = min(tree[i * 2], tree[i * 2 + 1]);
}

int query(int l, int r, int tl = 0, int tr = maxn, int i = 1){
    if (tl > r || tr < l) return INF;
    if (l <= tl && tr <= r) return tree[i];
    int tm = (tl + tr) / 2;
    return min(query(l, r, tl, tm, i * 2),
    query(l, r, tm + 1, tr, i * 2 + 1));
}

int get_left(int s, int w){
    int l = 1, r = s - 1, ans = s;
    while (l <= r){
        int mid = (l + r) / 2;
        int mn = query(mid, s);
        if (mn >= w) ans = mid, r = mid - 1;
        else l = mid + 1;
    }
    return ans;
}

int get_right(int s, int w){
    int l = s + 1, r = n, ans = s;
    while (l <= r){
        int mid = (l + r) / 2;
        int mn = query(s, mid - 1);
        if (mn >= w) ans = mid, l = mid + 1;
        else r = mid - 1;
    }
    return ans;
}

signed main(){
    fill(tree, tree + maxn * 4, INF);
    NYOOM;
    cin >> n >> m;
    for (int i = 1; i <= m; i++){
        cin >> u[i] >> v[i] >> d[i];
        update(i, d[i]);
    }
    cin >> q;
    FOR(i, q){
        int t; cin >> t; 
        if (t == 1){
            int b, r; cin >> b >> r;
            update(b, r);
        }   
        if (t == 2){
            int s, w; cin >> s >> w;
            int left = get_left(s, w);
            int right = get_right(s, w);
            cout << right - left + 1 << endl;
        }
    }
}

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