| # | 제출 시각 | 아이디 | 문제 | 언어 | 결과 | 실행 시간 | 메모리 |
|---|---|---|---|---|---|---|---|
| 1214291 | badge881 | Exam (eJOI20_exam) | C++20 | 0 ms | 0 KiB |
#include <bits/stdc++.h>
using namespace std;
long long pie(long long army) { return (1ll << army); }
signed main()
{
int n;
scanf("%d", &n);
int A[n], B[n];
for (int i = 0; i < n; i++)
scanf("%d", &A[i]);
for (int i = 0; i < n; i++)
scanf("%d", &B[i]);
int us[n + 1];
int nex = 2, bin = 0;
for (int i = 1; i <= n; i++)
{
us[i] = bin;
if (nex == i)
{
bin++;
nex <<= 1;
}
}
int spar[us[n] + 1][n];
for (int i = 0; i < n; i++)
spar[0][i] = A[i];
for (int i = 1; i <= us[n]; i++)
for (int j = 0; j <= n - pie(i); j++)
spar[i][j] = max(spar[i - 1][j], spar[i - 1][j + pie(i - 1)]);
if (n > 5000)
{
bool b = true;
for (int i = 1; i < n; i++)
if (B[i] != B[i - 1])
{
b = false;
break;
}
if (b)
{
bool dp[n + 1];
for (bool &x : dp)
x = false;
bool cur = false;
for (int i = 0; i < n; i++)
{
if (A[i] == B[0])
cur = true;
if (A[i] > B[0])
cur = false;
dp[i] |= cur;
}
cur = false;
for (int i = n - 1; i >= 0; i--)
{
if (A[i] == B[0])
cur = true;
if (A[i] > B[0])
cur = false;
dp[i] |= cur;
}
int ans = 0;
for (int i = 0; i < n; i++)
if (dp[i])
ans++;
cout << ans;
return;
}
else
{
map<int, int> mp;
for (int i = 1; i <= n; i++)
mp[A[i - 1]] = i;
vector<int> v;
for (int i = 0; i < n; i++)
{
int j = mp[B[i]];
if (j)
{
j--;
int boy = abs(i - j) + 1;
int mx = max(spar[us[boy]][min(i, j)], spar[us[boy]][max(i, j) - pie(us[boy]) + 1]);
if (mx <= B[i])
v.push_back(j + 1);
}
}
vector<int> ans;
for (int x : v)
{
int l = 0, r = ans.size();
while (l < r)
{
int m = (l + r) / 2;
if (ans[m] <= x)
l = m + 1;
else
r = m;
}
if (l == ans.size())
ans.push_back(x);
else
ans[l] = x;
}
cout << ans.size();
return;
}
}
int dp[n + 1][n + 1];
for (auto &x : dp)
for (auto &y : x)
y = -1;
dp[0][0] = 0;
for (int i = 0; i < n; i++)
{
for (int j = 0; j < n; j++)
{
if (dp[i][j] == -1)
continue;
if (A[j] == B[i])
{
int boy = abs(i - j) + 1;
int mx = max(spar[us[boy]][min(i, j)], spar[us[boy]][max(i, j) - pie(us[boy]) + 1]);
if (mx <= B[i])
{
dp[i + 1][j] = max(dp[i + 1][j], dp[i][j] + 1);
continue;
}
}
dp[i + 1][j] = max(dp[i + 1][j], dp[i][j]);
dp[i][j + 1] = max(dp[i][j + 1], dp[i][j]);
}
if (dp[i][n] != -1)
dp[i + 1][n] = max(dp[i + 1][n], dp[i][n]);
}
for (int i = 0; i < n; i++)
if (dp[n][i] != -1)
dp[n][i + 1] = max(dp[n][i + 1], dp[n][i]);
cout << dp[n][n];
}