Submission #1255209

#	Time	Username	Problem	Language	Result	Execution time	Memory
1255209		hoa208	Global Warming (CEOI18_glo)	C++20	10 / 100	184 ms	20904 KiB

glo

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; i++)
#define FORD(i, b, a) for (int i = (b), _a = (a); i >= _a; i--)
#define pa pair<ll, ll>
#define fi first
#define se second
#define bit(mask, j) ((mask >> j) & 1)
#define t_test int t;cin >> t;while(t--)
const   ll mod = 1e9 + 7;
const   ll INF = 1e18;
inline  void adm(ll &x){if(x>=mod)x%=mod;else if(x<0)x+=mod;}
//--------------------------------------------------------------------
const ll N = 2e5 + 10;
ll a[N];
unordered_map<ll, ll> mp;
ll BIT[N];
ll n;
ll pre[N], suf[N];
void update(ll x, ll val) {
    while(x <= n) {
        BIT[x] = max(BIT[x], val);
        x += x & -x;
    }  
}
ll get(ll x) {
    ll res = 0;
    while(x > 0) {
        res = max(BIT[x], res);
        x -= x & -x;
    }
    return res;
}

void update2(ll x, ll val) {
    while(x > 0) {
        BIT[x] = max(BIT[x], val);
        x -= x & -x;
    }  
}
ll get2(ll x) {
    ll res = 0;
    while(x <= n) {
        res = max(BIT[x], res);
        x += x & -x;
    }
    return res;
}
void hbmt() {
    ll x;
    vector<ll> b;
    cin >> n >> x;
    FOR(i, 1, n) {
        cin >> a[i];
        b.push_back(a[i]);
        b.push_back(a[i] + x);
        b.push_back(a[i] - x);
    }
    sort(b.begin(), b.end());
    b.erase(unique(b.begin(), b.end()), b.end());
    ll cnt = 0, ans = 0;
    for(auto e : b) {
        mp[e] = ++cnt;
    }
    FOR(i, 1, n) {
        ll val = get(mp[a[i]] - 1) + 1;
        pre[i] = val;
        ans = max(val, ans);
        update(mp[a[i]], val);
    }
    memset(BIT, 0, sizeof BIT);
    FORD(i, n, 1) {
        ll val = get2(mp[a[i]] + 1) + 1;
        suf[i] = val;
        update2(mp[a[i]], val);
    }
    memset(BIT, 0, sizeof BIT);
    FOR(i, 1, n) {
        ll val = get(mp[a[i] + x] - 1);
        ans = max(val + suf[i], ans);
        update(mp[a[i]], pre[i]);
    }
    memset(BIT, 0, sizeof BIT);
    FORD(i, n, 1) {
        ll val = get2(mp[a[i] - x] + 1);
        ans = max(val + pre[i], ans);
        update2(mp[a[i]], suf[i]);
    }
    cout << ans;
}

int main() {
    
    ios_base::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    
    if(fopen("hbmt.inp", "r")) {
        freopen("hbmt.inp", "r", stdin);
        freopen("hbmt.out", "w", stdout);
    }
    
    // t_test 
    hbmt();
    return 0;
}

Compilation message (stderr)

glo.cpp: In function 'int main()':
glo.cpp:99:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   99 |         freopen("hbmt.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
glo.cpp:100:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  100 |         freopen("hbmt.out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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