oj.uz

Submission #813509

# Submission time Handle Problem Language Result Execution time Memory
813509 2023-08-07T19:16:56 Z Sputnik123 Exam (eJOI20_exam) C++14
100 / 100
 224 ms 99528 KB 
#include <iostream>
#include <algorithm>
#include <cstring>
#include <vector>
#include <set>
#include <map>
#include <stack>
using namespace std;
typedef long long ll;
const int maxn = 1e5 + 10;
const int INF = 2e9;
int n;
int a[maxn], b[maxn];
int L[maxn], R[maxn];
int segment_tree[4 * maxn];
void solve_subtask2() {
    int x = b[0];
    int res = 0;
    for(int i = 0; i < n; i++) {
        if(a[i] == x) {
            res++;
            int j = i - 1;
            while(j >= 0 and a[j] <= x) {
                j--;
                res++;
            }
            j = i + 1;
            while(j < n and a[j] <= x) {
                res++;
                j++;
            }
            i = j - 1;
        }
    }
    cout << res << endl;
}
int dp[5005][5005];
int rec(int i, int j) {
    if(i < 0 or j < 0) {
        return 0;
    }
    if(dp[i][j] != -1) {
        return dp[i][j];
    }
    int res = 0;
    if(a[i] == b[j] and L[i] < j and R[i] > j) {
        res = max(res, rec(i, j - 1) + 1);
    }
    res = max(res, rec(i - 1, j));
    res = max(res, rec(i, j - 1));
    return dp[i][j] = res;
}
void build_tree(int L, int R, int node) {
    if(L == R) {
        segment_tree[node] = 0;
        return;
    }
    int middle = (L + R) / 2;
    build_tree(L, middle, 2 * node);
    build_tree(middle + 1, R, 2 * node + 1);
    segment_tree[node] = max(segment_tree[2 * node], segment_tree[2 * node + 1]);
}
int query(int i, int j, int L, int R, int node) {
    // L  R i L R j L R
    if(i <= L and R <= j) {
        return segment_tree[node];
    }
    if(R < i or j < L) {
        return 0;
    }
    int middle = (L + R) / 2;
    return max(query(i, j, L, middle, 2 * node), query(i, j, middle + 1, R, 2 * node + 1));
}
void update(int idx, int new_value, int L, int R, int node) {
    if(L == R) {
        segment_tree[node] = new_value;
        return;
    }
    int middle = (L + R) / 2;
    if(idx <= middle) {
        update(idx, new_value, L, middle, 2 * node);
    }
    else {
        update(idx, new_value, middle + 1, R, 2 * node + 1);
    }
    segment_tree[node] = max(segment_tree[2 * node], segment_tree[2 * node + 1]);
}
int main() {
    ios_base::sync_with_stdio(false);
    cin >> n;
    set<int> st;
    vector<int> t(n + 5);
    for(int i = 0; i < n; i++) {
        cin >> a[i];
        t[i + 1] = a[i];
    }
    for(int i = 0; i < n; i++) {
        cin >> b[i];
        st.insert(b[i]);
    }
    t[0] = INF;
    t[n + 1] = INF;
    stack<int> s;
    s.push(0);
    for(int i = 1; i <= n; i++) {
        while(t[s.top()] <= t[i]) {
            s.pop();
        }
        L[i - 1] = s.top() - 1;
        s.push(i);
    }
    while(!s.empty()) {
        s.pop();
    }
    s.push(n + 1);
    for(int i = n; i > 0; i--) {
        while(t[s.top()] <= t[i]) {
            s.pop();
        }
        R[i - 1] = s.top() - 1;
        s.push(i);
    }
    
    if((int) st.size() == 1) {
        solve_subtask2();
        return 0;
    }
    else if(n <= 5005){
        memset(dp, -1, sizeof dp);
        cout << rec(n - 1, n - 1) << endl;
    }
    else {
        build_tree(0, n - 1, 1);
        map<int, int> m;
        for(int i = 0; i < n; i++) {
            m[a[i]] = i;
        }
        
        for(int i = 0; i < n; i++) {
            map<int, int>::iterator it = m.find(b[i]);
            if(it != m.end()) {
                int idx = it->second;
                if(L[idx] < i and i < R[idx]) {
                    int dp = query(0, idx, 0, n - 1, 1);
                    update(idx, dp + 1, 0, n - 1, 1);
                }
            }
        }
        cout << query(0, n - 1, 0, n - 1, 1) << endl;
    }
    
    return 0;
}

Subtask #1
14.0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 31 ms 98252 KB Output is correct
2 Correct 31 ms 98348 KB Output is correct
3 Correct 32 ms 98356 KB Output is correct
4 Correct 32 ms 98388 KB Output is correct
5 Correct 32 ms 98256 KB Output is correct
6 Correct 32 ms 98268 KB Output is correct

Subtask #2
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 4 ms 1076 KB Output is correct
3 Correct 15 ms 3440 KB Output is correct
4 Correct 10 ms 2652 KB Output is correct
5 Correct 20 ms 4300 KB Output is correct
6 Correct 11 ms 2644 KB Output is correct
7 Correct 14 ms 2772 KB Output is correct
8 Correct 19 ms 4220 KB Output is correct

Subtask #3
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 31 ms 98388 KB Output is correct
2 Correct 34 ms 98452 KB Output is correct
3 Correct 53 ms 98780 KB Output is correct
4 Correct 145 ms 99348 KB Output is correct
5 Correct 161 ms 99356 KB Output is correct
6 Correct 163 ms 99528 KB Output is correct

Subtask #4
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 157 ms 99508 KB Output is correct
2 Correct 28 ms 5448 KB Output is correct
3 Correct 78 ms 12128 KB Output is correct
4 Correct 79 ms 12880 KB Output is correct
5 Correct 91 ms 12280 KB Output is correct
6 Correct 86 ms 11468 KB Output is correct
7 Correct 80 ms 12428 KB Output is correct
8 Correct 77 ms 11524 KB Output is correct
9 Correct 96 ms 12296 KB Output is correct
10 Correct 63 ms 12068 KB Output is correct

Subtask #5
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 31 ms 98252 KB Output is correct
2 Correct 31 ms 98348 KB Output is correct
3 Correct 32 ms 98356 KB Output is correct
4 Correct 32 ms 98388 KB Output is correct
5 Correct 32 ms 98256 KB Output is correct
6 Correct 32 ms 98268 KB Output is correct
7 Correct 39 ms 98248 KB Output is correct
8 Correct 32 ms 98360 KB Output is correct
9 Correct 30 ms 98352 KB Output is correct
10 Correct 31 ms 98400 KB Output is correct
11 Correct 30 ms 98380 KB Output is correct
12 Correct 31 ms 98376 KB Output is correct
13 Correct 30 ms 98380 KB Output is correct
14 Correct 33 ms 98332 KB Output is correct

Subtask #6
22.0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 31 ms 98252 KB Output is correct
2 Correct 31 ms 98348 KB Output is correct
3 Correct 32 ms 98356 KB Output is correct
4 Correct 32 ms 98388 KB Output is correct
5 Correct 32 ms 98256 KB Output is correct
6 Correct 32 ms 98268 KB Output is correct
7 Correct 31 ms 98388 KB Output is correct
8 Correct 34 ms 98452 KB Output is correct
9 Correct 53 ms 98780 KB Output is correct
10 Correct 145 ms 99348 KB Output is correct
11 Correct 161 ms 99356 KB Output is correct
12 Correct 163 ms 99528 KB Output is correct
13 Correct 39 ms 98248 KB Output is correct
14 Correct 32 ms 98360 KB Output is correct
15 Correct 30 ms 98352 KB Output is correct
16 Correct 31 ms 98400 KB Output is correct
17 Correct 30 ms 98380 KB Output is correct
18 Correct 31 ms 98376 KB Output is correct
19 Correct 30 ms 98380 KB Output is correct
20 Correct 33 ms 98332 KB Output is correct
21 Correct 31 ms 98400 KB Output is correct
22 Correct 45 ms 98560 KB Output is correct
23 Correct 1 ms 468 KB Output is correct
24 Correct 224 ms 99348 KB Output is correct
25 Correct 174 ms 99348 KB Output is correct
26 Correct 181 ms 99288 KB Output is correct
27 Correct 180 ms 99284 KB Output is correct
28 Correct 159 ms 99464 KB Output is correct
29 Correct 172 ms 99424 KB Output is correct
30 Correct 155 ms 99404 KB Output is correct
31 Correct 184 ms 99424 KB Output is correct
32 Correct 155 ms 99480 KB Output is correct