Submission #1172930

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Source Code Expand

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

template <typename T>
using Matrix = vector<vector<T>>;

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    string s; cin >> s;
    const auto n = int(s.size());

    auto f = Matrix<int>(n+2, vector<int>(27, n+1));
    for (auto i = n-1; i >= 0; i--)
    {
        const auto start = s[i]-'a';
        f[i][start] = i+1;
        for (auto c = start+1; c <= 26; c++)
            f[i][c] = f[f[i][c-1]][c-1];
        for (auto c = 0; c < start; c++)
            f[i][c] = f[f[i][26]][c];
    }

    auto children = vector<vector<int>>(n+2);
    children[n+1].push_back(n);
    for (auto i = 0; i < n; i++)
        children[f[i][26]].push_back(i);

    auto time = 0;
    auto start_times = vector<int>(n+2), exit_times = vector<int>(n+2);
    const function<void(int)> dfs = [&](const int v)
    {
        start_times[v] = time++;
        for (const auto c : children[v])
            dfs(c);
        exit_times[v] = time;
    };
    dfs(n+1);

    int Q; cin >> Q;
    for (auto q = 0; q < Q; q++)
    {
        int l, r; cin >> l >> r;
        l--; r--;
        cout << (start_times[r+1] <= start_times[l] && start_times[l] < exit_times[r+1] ? "Yes": "No") << "\n";
    }
}

Submission Info

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