Submission #1083341

#	Time	Username	Problem	Language	Result	Execution time	Memory
1083341		sh1ro	Global Warming (CEOI18_glo)	C++14	100 / 100	49 ms	7004 KiB

glo

#include <bits/stdc++.h>
#define int long long
#define endl '\n'
#define fi first
#define se second
using namespace std;
const int N = 2e5 + 4;
const int oo = 1e18;
const int mod = (1 << 9);
int t, n, q, m, k, ans = 0, a[N], dp[N], f[N]{};
vector<int>v;

void solve(){
    cin >> n >> k;
    for (int i = 0; i < n; i++)cin >> a[i], dp[i] = oo;
    for (int i = 0; i < n; i++){
        m = lower_bound(dp, dp + n, a[i]) - dp;
        f[i] = m + 1;
        dp[m] = a[i];
        ans = max(ans, f[i]);
    }
    for (int i = 0; i < n; i++)dp[i] = oo;
    for (int i = n - 1; i >= 0; i--){
        m = lower_bound(dp, dp + n, k - a[i]) - dp;
        ans = max(ans, f[i] + m);
        m = lower_bound(dp, dp + n, -a[i]) - dp;
        dp[m] = -a[i];
    }
    cout << ans;
}
main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    //freopen("prime.inp", "r", stdin); freopen("prime.out", "w", stdout);
    t = 1;
    //cin >> t;
    while (t--)solve();
    return 0;
}

Compilation message (stderr)

glo.cpp:31:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   31 | main() {
      | ^~~~

• 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