Submission #455157

#	Time	Username	Problem	Language	Result	Execution time	Memory
455157		Yuisuyuno	Global Warming (CEOI18_glo)	C++14	100 / 100	65 ms	8540 KiB

glo

//Nguyen Huu Hoang Minh
#include <bits/stdc++.h>
#define sz(x) int(x.size())
#define all(x) x.begin(),x.end()
#define reset(x) memset(x, 0,sizeof(x))
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define N 200005
#define remain(x) if (x > MOD) x -= MOD
#define ii pair<int, int>
#define iiii pair< ii , ii >
#define viiii vector< iiii >
#define vi vector<int>
#define vii vector< ii >
#define bit(x, i) (((x) >> (i)) & 1)
#define Task "test"
#define int long long

using namespace std;

typedef long double ld;
const int inf = 1e10;
const int minf = -1e10;

int n, x;
int a[N];

void readfile()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);cout.tie(0);
    if (fopen(Task".inp","r"))
    {
        freopen(Task".inp","r",stdin);
        //freopen(Task".out","w",stdout);
    }
    cin >> n >> x;
    for(int i=1; i<=n; i++) cin >> a[i];
}

int L[N];
int R[N];

void proc()
{
    vector<int> b(n+1,inf);
    b[0] = minf;
    for(int i=1; i<=n; i++){
        int k = lower_bound(all(b),a[i])-b.begin();
        L[i] = k;
        b[k] = a[i];
    }
    //for(int i=1; i<=n; i++) cout << L[i] << ' ';
    b = vector<int>(n+1,inf);
    int ans=0;
    for(int i=n; i>=1; i--){
        int k = lower_bound(all(b),-a[i]+x)-b.begin();
        //cout << k << " \n"[i==1];
        ans = max(ans,L[i]+k);
        k = lower_bound(all(b),-a[i])-b.begin();
        b[k] = -a[i];
    }
    cout << ans;
}

signed main()
{
    readfile();
    proc();
    return 0;
}

Compilation message (stderr)

glo.cpp: In function 'void readfile()':
glo.cpp:36:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   36 |         freopen(Task".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

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