Submission #1274968

#	Time	Username	Problem	Language	Result	Execution time	Memory
1274968		hynmj	Construction Project 2 (JOI24_ho_t2)	C++20	16 / 100	2095 ms	21876 KiB

Main

#include <bits/stdc++.h>
#define pi pair<int, int>
#define int long long
#define ff first
#define ss second
using namespace std;
const int N = 2e5 + 7;
vector<pi> graph[N];
typedef long long ll;

// Structure of the node
struct Node
{

    ll value;
    struct Node *L, *R;
};

// Structure to get the newly formed
// node
struct Node *getnode()
{
    struct Node *temp = new struct Node;
    temp->value = 0;
    temp->L = NULL;
    temp->R = NULL;
    return temp;
}

// Creating the Root node
struct Node *root;

// Function to perform the point update
// on the dynamic segment tree
void UpdateHelper(struct Node *curr, ll index,
                  ll L, ll R, ll val)
{

    // If the index is not overlapping
    // with the index
    if (L > index || R < index)
        return;

    // If the index is completely overlapping
    // with the index
    if (L == R && L == index)
    {

        // Update the value of the node
        // to the given value
        curr->value += val;
        return;
    }

    // Computing the middle index if none
    // of the above base cases are satisfied
    ll mid = L - (L - R) / 2;
    ll sum1 = 0, sum2 = 0;

    // If the index is in the left subtree
    if (index <= mid)
    {

        // Create a new node if the left
        // subtree is null
        if (curr->L == NULL)
            curr->L = getnode();

        // Recursively call the function
        // for the left subtree
        UpdateHelper(curr->L, index, L, mid, val);
    }

    // If the index is in the right subtree
    else
    {

        // Create a new node if the right
        // subtree is null
        if (curr->R == NULL)
            curr->R = getnode();

        // Recursively call the function
        // for the right subtree
        UpdateHelper(curr->R, index, mid + 1, R, val);
    }

    // Storing the sum of the left subtree
    if (curr->L)
        sum1 = curr->L->value;

    // Storing the sum of the right subtree
    if (curr->R)
        sum2 = curr->R->value;

    // Storing the sum of the children into
    // the node's value
    curr->value = sum1 + sum2;
    return;
}

// Function to find the sum of the
// values given by the range
ll queryHelper(struct Node *curr, ll a,
               ll b, ll L, ll R)
{

    // Return 0 if the root is null
    if (curr == NULL)
        return 0;

    // If the index is not overlapping
    // with the index, then the node
    // is not created. So sum is 0
    if (L > b || R < a)
        return 0;

    // If the index is completely overlapping
    // with the index, return the node's value
    if (L >= a && R <= b)
        return curr->value;

    ll mid = L - (L - R) / 2;

    // Return the sum of values stored
    // at the node's children
    return queryHelper(curr->L, a, b, L, mid) + queryHelper(curr->R, a, b, mid + 1, R);
}

// Function to call the queryHelper
// function to find the sum for
// the query
ll query(int L, int R)
{
    return queryHelper(root, L, R, 0, 1e15);
}

// Function to call the UpdateHelper
// function for the point update
void update(int index, int value)
{
    UpdateHelper(root, index, 0, 1e15, value);
}

vector<int> dijkstra(int start)
{
    vector<int> dist(N, 1e18);
    priority_queue<pi, vector<pi>, less<pi>> q;
    q.push({0, start});
    dist[start] = 0;
    int node, weight;
    while (q.size())
    {
        node = q.top().ss;
        q.pop();
        for (auto i : graph[node])
        {
            if (dist[i.ss] > dist[node] + i.ff)
            {
                dist[i.ss] = dist[node] + i.ff;
                q.push({dist[i.ss], i.ss});
            }
        }
    }
    return dist;
}

void solve()
{
    root = getnode();
    int n, m;
    cin >> n >> m;
    int s, t, l, k;
    cin >> s >> t >> l >> k;

    int u, v, w;

    for (int i = 0; i < m; i++)
    {
        cin >> u >> v >> w;
        graph[u].push_back({w, v});
        graph[v].push_back({w, u});
    }
    vector<int> sdist = dijkstra(s);
    vector<int> tdist = dijkstra(t);
    if (sdist[t] <= k)
    {
        cout << n * (n - 1) / 2;
        return;
    }
    int ans1 = 0;
    int ans = 0;

    // cout << ans1 << endl;
    // cout << "------" << endl;
    // update(0, 1);
    for (int i = 1; i <= n; i++)
    {
        if (tdist[i] <= 1e18)
            update(tdist[i], 1);
        // cout << tdist[i] << " ";
    }
    // cout << endl;
    for (int i = 1; i <= n; i++)
    {
        // cout << sdist[i] << " ";
    }
    // cout << endl;
    // cout << query(0, 2) << endl;

    for (int i = 1; i <= n; i++)
    {
        // continue;
        if (tdist[i] < 1e18)
            update(tdist[i], -1);
        int kk = query(0, k - l - sdist[i]);
        ans += kk;
        // cout << "for " << i << " we have " << kk << endl;
        // cout << "ans  = " << ans << endl;
    }
    root = getnode();

    for (int i = 1; i <= n; i++)
    {
        if (sdist[i] <= 1e18)
            update(sdist[i], 1);
        // cout << query(0, 1) << endl;
    }

    for (int i = 1; i <= n; i++)
    {
        // continue;
        if (sdist[i] < 1e18)
            update(sdist[i], -1);
        int kk = query(0, k - l - tdist[i]);
        ans += kk;
        // cout << "for " << i << " we have " << kk << endl;
        // cout << "ans  = " << ans << endl;
    }

    cout << ans << endl;
}

signed main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(NULL);
    cout.tie(NULL);
    int t = 1;
    // cin >> t;
    while (t--)
    {
        solve();
        cout << endl;
    }
    return 0;
}

• Subtask 1: 0 / 8
• Subtask 2: 16 / 16
• Subtask 3: 0 / 29
• Subtask 4: 0 / 47