Submission #1172965

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Source Code Expand

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

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

template <typename T>
Matrix<T> matrix(const int R, const int C, const T x = T()) { return Matrix<T>(R, vector<T>(C, x)); }

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, 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];
    }

    const auto log = 18;
    auto jumps = matrix<int>(log+1, n+2);
    for (auto i = 0; i < n+2; i++)
        jumps[0][i] = f[i][26];
    for (auto k = 1; k <= log; k++)
        for (auto i = 0; i < n+2; i++)
            jumps[k][i] = jumps[k-1][jumps[k-1][i]];

    int Q; cin >> Q;
    for (auto q = 0; q < Q; q++)
    {
        int l, r; cin >> l >> r;
        l--; r--;

        auto x = l;
        for (auto k = log; k >= 0; k--)
            if (jumps[k][x] <= r+1) x = jumps[k][x];
        cout << (x == r+1 ? "Yes" : "No") << "\n";
    }
}

Submission Info

Judge Result