Submission #882138

#	Time	Username	Problem	Language	Result	Execution time	Memory
882138		skywwla	Global Warming (CEOI18_glo)	C++17	0 / 100	2032 ms	3292 KiB

glo

#include <bits/stdc++.h>

using namespace std ;
using ll = long long ;

const int N = 2e5 + 5 ;

int n , x , a[N], l[N], r[N] ;

int findLIS() {
    vector<int> d ;
    for (int i = 1 ; i <= n ; i++) {
        auto it = upper_bound(d.begin(), d.end(), a[i]) ;
        if (it == d.end()) d.push_back(a[i]) ;
        else *it = a[i] ;
    }
    return d.size() ;
}

int32_t main() {
    ios::sync_with_stdio(false) ;
    cin.tie(nullptr) ;
    cin >> n >> x ;
    for (int i = 1 ; i <= n ; i++) {
        cin >> a[i] ;
    }
    for (int i = 1 ; i <= n ; i++) {
        l[i] = a[i] - x ;
        r[i] = a[i] + x ;
    }
    int ret = findLIS() ;
    if (!x) {
        cout << ret ;
        return 0 ;
    }
    vector<int> dp ;
    for (int i = 1 ; i <= n ; i++) {
        auto it = lower_bound(dp.begin(), dp.end(), a[i]) ;
        int mx = it - dp.begin() + 1 ;
        if (it == dp.end()) dp.push_back(a[i]) ;
        else *it = a[i] ;
        deque<int> dp1 ;
        for (int j = n ; j > i ; j--) {
            auto it1 = lower_bound(dp1.begin(), dp1.end(), a[j]) ;
            int pos = it1 - dp1.begin() + 1 ;
            if (it1 == dp1.begin()) dp1.push_front(a[j]) ;
            else {
                it1-- ;
                *it1 = a[j] ;
            }
            int cur = it1 - dp1.begin() + 1 ;
            if (a[j] - 1 >= l[i] && a[j] - 1 <= r[i]) {
//                cout << mx + cur <<  "\n" ;
//                cout << mx << ' ' << l[i] << ' ' << r[i] << ' ' << i << ' ' << dp1.size() << ' ' << j << "\n" ;
                ret = max(ret, mx + cur) ;
            }
        }
    }
    cout << ret ;
    return 0 ;
}

Compilation message (stderr)

glo.cpp: In function 'int32_t main()':
glo.cpp:45:17: warning: unused variable 'pos' [-Wunused-variable]
   45 |             int pos = it1 - dp1.begin() + 1 ;
      |                 ^~~

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