提出 #49318086

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ソースコード 拡げる

#include <bits/stdc++.h>
#include <atcoder/modint>

namespace {
    using ModInt [[maybe_unused]] = atcoder::modint998244353;
    using Num [[maybe_unused]] = long long int;
    using Vec [[maybe_unused]] = std::vector<Num>;
    using Set [[maybe_unused]] = std::set<Num>;
    using Mset [[maybe_unused]] = std::multiset<Num>;
    using Edges [[maybe_unused]] = std::vector<std::vector<Num>>;

    template<typename T>
    using Q [[maybe_unused]] = std::queue<T>;

    template<typename T>
    using PQ [[maybe_unused]] = std::priority_queue<T, std::vector<T>, std::greater<T>>;
}

void solve(std::istream& is, std::ostream& os) {
    Num n {0};
    is >> n;

    Vec hset(n);
    for(auto& a : hset) {
        is >> a;
    }

    Vec left_height(n+1);
    for(Num i{0}; i<n; ++i) {
        left_height.at(i+1) = std::min(left_height.at(i) + 1, hset.at(i));
    }

    Vec right_height(n+1);
    for(Num i{n}; i>=1; --i) {
        right_height.at(i-1) = std::min(right_height.at(i) + 1, hset.at(i-1));
    }

    Num answer {0};
    for(Num i{1}; i<=n; ++i) {
        answer = std::max(answer, std::min(left_height.at(i), right_height.at(i-1)));
    }

    os << answer << "\n";
}

int main(void) {
    solve(std::cin, std::cout);
    return 0;
}

提出情報

ジャッジ結果