Submission #1315037

#	Time	Username	Problem	Language	Result	Execution time	Memory
1315037		thanhbinh13	Global Warming (CEOI18_glo)	C++20	100 / 100	62 ms	6660 KiB

glo

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

const int N = 2e5+5;
long long n,X,t[N];
long long b[N];
long long pre[N],suf[N];
long long bs1(long long x,long long l,long long r) {
    long long m = 0;
    while(l <= r) {
        long long mid = (l+r) /2;
        if (t[b[mid]] < x) {
            m = mid;
            l = mid+1;
        } else r = mid-1;
    }
    return b[m];
}
long long bs2(long long x,long long l,long long r) {
    long long m = 0;
    while(l <= r) {
        long long mid = (l+r) /2;
        if (t[b[mid]] > x) {
            m = mid;
            l = mid+1;
        } else r = mid-1;
    }
    return b[m];
}
long long bs3(long long x,long long l,long long r) {
    long long m = 0;
    while(l <= r) {
        long long mid = (l+r) /2;
        if (t[b[mid]] > x-X) {
            m = mid;
            l = mid+1;
        } else r = mid-1;
    }
    return b[m];
}
long long bs4(long long x,long long l,long long r) {
    long long m = 0;
    while(l <= r) {
        long long mid = (l+r) /2;
        if (t[b[mid]] < x+X) {
            m = mid;
            l = mid+1;
        } else r = mid-1;
    }
    return b[m];
}
long long ans = 0;
int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    cin >> n >> X;
    for (int i= 1; i <= n;i ++) {
        cin >> t[i];
    } 
    long long res = 0;
    for (int i = 1; i <= n; i++) {
        b[i] = 0;
    }
    for (int i = 1;i <=n; i++) {
        pre[i] = pre[bs1(t[i],1,res)]+1;
        b[pre[i]] = i;
        res=  max(res,pre[i]);
    }
    res = 0;
    for (int i = 1; i <= n; i++) {
        b[i] = 0;
    }
    for (int i = n;i >= 1; i--) {
        suf[i] = suf[bs2(t[i],1,res)]+1;
        b[suf[i]] = i;
        res=  max(res,suf[i]);
    }
    res = 0;
    for (int i = 1; i <= n; i++) {
        b[i] = 0;
    }
    for (int i = n;i >= 1; i--) {
        // suf[i] = suf[bs(t[i],1,res)]+1;
        ans = max(ans,pre[i]+suf[bs3(t[i],1,res)]);
        b[suf[i]] = i;
        res=  max(res,suf[i]);
    }
    res = 0;
    for (int i = 1; i <= n; i++) {
        b[i] = 0;
    }
    for (int i = 1;i <= n; i++) {
        // suf[i] = suf[bs(t[i],1,res)]+1;
        ans = max(ans,pre[bs4(t[i],1,res)]+suf[i]);
        b[pre[i]] = i;
        res=  max(res,pre[i]);
    }
    cout << ans;
}

• 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