Submission #854208

#	Time	Username	Problem	Language	Result	Execution time	Memory
854208		anhphant	Global Warming (CEOI18_glo)	C++14	45 / 100	2064 ms	7304 KiB

glo

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

ll N, X, A[500007];

void initialize() {
    ios_base :: sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    if (fopen("FILE.INP", "r")) {
        freopen("FILE.INP", "r", stdin);
        freopen("FILE.OUT", "w", stdout);
    }

    cin >> N >> X;
    for(int i = 1; i <= N; ++i) cin >> A[i];
}

namespace subtask1 {
    ll LIS(vector<ll> v) {
        //for(int id = 1; id <= N; ++id) cerr << v[id] << " "; cerr << endl;
        ll ans = 0;
        for(ll mask = 1; mask < (1 << N); ++mask) {
            //cerr << "mask = " << mask << endl;
            ll last_value = -1e12;
            bool flag = 1;
            for(ll i = 0; i < N; ++i) {
                if (!(mask & (1 << i))) continue;
                if (last_value >= v[i + 1]) {
                    flag = 0;
                    break;
                }
                last_value = v[i + 1];
            }
            if (flag) ans = max(ans, ll(__builtin_popcountll(mask)));
        }
        return ans;
    }

    void solve() {
        vector<ll> arr(N + 7, 0LL);
        for(int i = 1; i <= N; ++i) arr[i] = A[i];
        ll res = 0;

        for(ll x = -X; x <= X; ++x) {
            //cerr << "x = " << x << endl;
            for(int i = 1; i <= N; ++i) {
                vector<ll> v = arr;
                for(int j = i; j <= N; ++j) {
                    v[j] += x;
                    res = max(res, LIS(v));
                    //cerr << i << " " << j << " " << LIS(v) << endl;
                }
            }
        }

        cout << res << endl;
    }

    void process() {
        solve();
    }
}

namespace subtask2 {
    ll LIS(vector<ll> v) {
        vector<ll> bslen(N + 1, 0LL);
        for(int i = 1; i <= N; ++i) bslen[i] = 1e18;
        ll ans = 0;

        for(ll i = 1; i <= N; ++i) {
            ll k = lower_bound(bslen.begin(), bslen.end(), v[i]) - bslen.begin() - 1;
            ans = max(ans, k + 1);
            bslen[k + 1] = min(bslen[k + 1], v[i]);
        }

        return ans;
    }

    void solve() {
        vector<ll> arr(N + 7, 0LL);
        for(int i = 1; i <= N; ++i) arr[i] = A[i];
        ll res = 0;

        for(ll x = -X; x <= X; ++x) {
            //cerr << "x = " << x << endl;
            for(int i = 1; i <= N; ++i) {
                vector<ll> v = arr;
                for(int j = i; j <= N; ++j) {
                    v[j] += x;
                    res = max(res, LIS(v));
                    //cerr << i << " " << j << " " << LIS(v) << endl;
                }
            }
        }

        cout << res << endl;
    }

    void process() {
        solve();
    }
}

namespace subtask3 {
    ll LIS(vector<ll> v) {
        vector<ll> bslen(N + 1, 0LL);
        for(int i = 1; i <= N; ++i) bslen[i] = 1e18;
        ll ans = 0;

        for(ll i = 1; i <= N; ++i) {
            ll k = lower_bound(bslen.begin(), bslen.end(), v[i]) - bslen.begin() - 1;
            ans = max(ans, k + 1);
            bslen[k + 1] = min(bslen[k + 1], v[i]);
        }

        return ans;
    }

    void solve() {
        vector<ll> arr(N + 7, 0LL);
        for(int i = 1; i <= N; ++i) arr[i] = A[i];
        ll res = LIS(arr);

        for(int i = 1; i <= N; ++i) {
            arr[i] -= X;
            res = max(res, LIS(arr));
        }

        cout << res << endl;
    }

    void process() {
        solve();
    }
}

namespace subtask4 {
    ll LIS(vector<ll> v) {
        vector<ll> bslen(N + 1, 0LL);
        for(int i = 1; i <= N; ++i) bslen[i] = 1e18;
        ll ans = 0;

        for(ll i = 1; i <= N; ++i) {
            ll k = lower_bound(bslen.begin(), bslen.end(), v[i]) - bslen.begin() - 1;
            ans = max(ans, k + 1);
            bslen[k + 1] = min(bslen[k + 1], v[i]);
        }

        return ans;
    }

    void solve() {
        vector<ll> arr(N + 7, 0LL);
        for(int i = 1; i <= N; ++i) arr[i] = A[i];
        cout << LIS(arr);
    }

    void process() {
        solve();
    }
}

namespace subtask5 {
    ll LIS(vector<ll> v, ll x) {
        vector<ll> type1(N + 1, 0LL), type2(N + 1, 0LL), type3(N + 1, 0LL);
        for(int i = 1; i <= N; ++i) {
            type1[i] = type2[i] = type3[i] = 1e18;
        }

        int ans = 0;

        for(ll i = 1; i <= N; ++i) {
            int DP1 = lower_bound(type1.begin(), type1.end(), A[i]) - type1.begin() - 1;

            int DP2 = lower_bound(type2.begin(), type2.end(), A[i]) - type2.begin() - 1;
            DP2 = max(DP2, int(lower_bound(type1.begin(), type1.end(), A[i] + x) - type1.begin() - 1));

            int DP3 = lower_bound(type3.begin(), type3.end(), A[i]) - type3.begin() - 1;
            DP3 = max(DP2, int(lower_bound(type2.begin(), type2.end(), A[i] - x) - type2.begin() - 1));

            ans = max({ans, DP1 + 1, DP2 + 1, DP3 + 1});

            DP1++;
            DP2++;
            DP3++;
            type1[DP1] = min(type1[DP1], A[i]);
            type2[DP2] = min(type2[DP2], A[i]);
            type3[DP3] = min(type3[DP3], A[i]);
        }

        return ans;
    }

    void solve() {
        vector<ll> arr(N + 7, 0LL);
        for(int i = 1; i <= N; ++i) arr[i] = A[i];
        ll res = 0;

        for(ll x = -X; x <= X; ++x) {
            res = max(res, LIS(arr, x));
        }

        cout << res << endl;
    }

    void process() {
        solve();
    }
}

int main() {
    initialize();
    if (N <= 50) subtask2 :: process();
    else if (X == 0) subtask4 :: process();
    else if (N <= 1000) subtask3 :: process();
    else subtask5 :: process();
}

Compilation message (stderr)

glo.cpp: In function 'void initialize()':
glo.cpp:11:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   11 |         freopen("FILE.INP", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
glo.cpp:12:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   12 |         freopen("FILE.OUT", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 0 / 13
• Subtask 4: 10 / 10
• Subtask 5: 20 / 20
• Subtask 6: 0 / 17
• Subtask 7: 0 / 25