Submission #578785

#	Time	Username	Problem	Language	Result	Execution time	Memory
578785		Forested	Global Warming (NOI13_gw)	C++17	40 / 40	269 ms	17612 KiB

gw

#ifndef LOCAL
#define FAST_IO
#endif

// ===== template.hpp =====
#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <cmath>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <tuple>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

#define OVERRIDE(a, b, c, d, ...) d
#define REP2(i, n) for (i32 i = 0; i < (i32) (n); ++i)
#define REP3(i, m, n) for (i32 i = (i32) (m); i < (i32) (n); ++i)
#define REP(...) OVERRIDE(__VA_ARGS__, REP3, REP2)(__VA_ARGS__)
#define PER(i, n) for (i32 i = (i32) (n) - 1; i >= 0; --i)
#define ALL(x) begin(x), end(x)

using namespace std;

using u32 = unsigned int;
using u64 = unsigned long long;
using u128 = __uint128_t;
using i32 = signed int;
using i64 = signed long long;
using i128 = __int128_t;
using f64 = double;
using f80 = long double;

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

template <typename T>
bool chmin(T &x, const T &y) {
    if (x > y) {
        x = y;
        return true;
    }
    return false;
}
template <typename T>
bool chmax(T &x, const T &y) {
    if (x < y) {
        x = y;
        return true;
    }
    return false;
}

istream &operator>>(istream &is, i128 &x) {
    i64 v;
    is >> v;
    x = v;
    return is;
}
ostream &operator<<(ostream &os, i128 x) {
    os << (i64) x;
    return os;
}
istream &operator>>(istream &is, u128 &x) {
    u64 v;
    is >> v;
    x = v;
    return is;
}
ostream &operator<<(ostream &os, u128 x) {
    os << (u64) x;
    return os;
}

[[maybe_unused]] constexpr i32 INF = 1000000100;
[[maybe_unused]] constexpr i64 INF64 = 3000000000000000100;

#ifdef FAST_IO
__attribute__((constructor)) void fast_io() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout << fixed << setprecision(10);
}
#endif
// ===== template.hpp =====

#ifdef DEBUGF
#include "cpl/template/debug.hpp"
#else
#define DBG(x) (void) 0
#endif

int main() {
    i32 n;
    cin >> n;
    Vec<i32> h(n);
    REP(i, n) {
        cin >> h[i];
    }
    
    if (n == 1) {
        cout << 1 << '\n';
        exit(0);
    }
    
    Vec<i32> idx(n);
    iota(ALL(idx), 0);
    sort(ALL(idx), [&](i32 i, i32 j) -> bool {
        return h[i] < h[j];
    });
    
    i32 cnt = 1;
    Vec<bool> alive(n, true);
    i32 ans = cnt;
    REP(i, n) {
        i32 isl = idx[i];
        if (isl == 0) {
            if (!alive[isl + 1]) {
                --cnt;
            }
        } else if (isl == n - 1) {
            if (!alive[isl - 1]) {
                --cnt;
            }
        } else {
            if (alive[isl - 1] && alive[isl + 1]) {
                ++cnt;
            } else if (!alive[isl - 1] && !alive[isl + 1]) {
                --cnt;
            }
        }
        alive[isl] = false;
        if (i == n - 1 || h[idx[i]] != h[idx[i + 1]]) {
            chmax(ans, cnt);
        }
    }
    cout << ans << '\n';
}

• Subtask 1: 6 / 6
• Subtask 2: 6 / 6
• Subtask 3: 7 / 7
• Subtask 4: 10 / 10
• Subtask 5: 11 / 11