Submission #769604

# Submission time Handle Problem Language Result Execution time Memory
769604 2023-06-29T20:38:10 Z gg123_pe Sequence (APIO23_sequence) C++17
40 / 100
306 ms 33468 KB
#include "sequence.h"
#include <bits/stdc++.h> 
using namespace std;

#define f(i,a,b) for(int i = a; i < b; i++)
#define fa(i,a,b) for(int i = a; i >= b; i--)

const int N = 5e5 + 5; 

int n; 
int bit[N], c[N];
vector <pair<int,int>> pos[N]; 

void upd(int x, int val){
    for(; x < N; x = (x|(x+1))) bit[x] += val; 
}
int sum(int x){
    int res = 0;
    for(; x >= 0; x = (x&(x+1)) - 1) res += bit[x];  
    return res; 
}
int get(int x){
    int l = 1, r = n; 
    while(l < r){
        int m = (l+r)>>1; 
        if(sum(m) >= x) r = m; 
        else l = m+1; 
    }
    return c[l]; 
}
int subtask_2(vector <int> A){
    int ans = 1; 
    f(i,0,n){
        c[A[i]]++; 
        upd(A[i], 1); 

        f(j,i,n){
            int l = j - i + 1; 
            if(l&1){
                ans = max(ans, get((l+1)/2)); 
            }
            else{
                ans = max(ans, get(l/2)); 
                ans = max(ans, get(l/2 + 1)); 
            }
            if(j+1 < n) {
                c[A[j+1]]++; 
                upd(A[j+1], 1); 
            }
        }
        f(j,i,n){
            c[A[j]]--; 
            upd(A[j], -1); 
        }
    }
    return ans;
}
int id(int pos){
    if(pos == 0) return 0; 
    if(c[1] >= pos) return 1; 
    if(c[1] + c[2] >= pos) return 2; 
    return 3; 
}
int res(vector <int> v){
    vector <int> aux, mini; 
    int len = v.size(), ans = 1; 
    f(i,0,len) {
        aux.push_back(v[i] - 2*i); 
        mini.push_back(v[i] - 2*i); 
    }
    fa(i,len-2,0) mini[i] = min(mini[i+1], mini[i]); 

    f(i,0,len-1){
        int ult = aux[i] + 1; // <= ult
        if(mini[i+1] > ult) continue; 
        int l = i+1, r = len-1; 
        while(l < r){
            int m = (l+r+1)>>1; 
            if(mini[m] > ult) r = m-1;  
            else l = m; 
        }
        ans = max(ans, l-i+1); 
    }
    return ans;     
}
int subtask_4(vector <int> A){
    for(int x: A) c[x]++; 
    int p1 = 0, p2 = 0; 
    if(n&1) p1 = (n+1)/2; 
    else p1 = n/2, p2 = p1 + 1; 

    if(id(p1) == 1 or id(p1) == 3) return c[id(p1)]; 
    if(id(p2) == 1 or id(p2) == 3) return c[id(p2)]; 
    if(c[2] > c[1] and c[2] > c[3]) return c[2]; 

    int ans = c[2];
    vector <int> P1, P3; 
    f(i,0,n){
        if(A[i] == 1) P1.push_back(i); 
        if(A[i] == 3) P3.push_back(i); 
    }
    ans = max(ans, res(P1)); 
    ans = max(ans, res(P3)); 
    return ans; 
}
bool is(int l, int r, int ty){
    if(l != r) return 1; 
    return l%2 == ty; 
}
int subtask_3(vector <int> A){
    int ans = 0, id = 0; 
    while(id < n){
        int c = 0, ini = id+1, comp = A[id]; 
        while(A[id] == comp and id < n) c++, id++; 
        ans = max(ans, c);  
        pos[comp].push_back({ini, ini + c - 1}); 
    } 
    f(i,1,n+1){
        if(pos[i].size() != 2) continue; 
        int l1 = pos[i][0].first, r1 = pos[i][1].second; 
        int l2 = pos[i][1].first, r2 = pos[i][1].second; 
        int C = r1 - l1 + r2 - l2 + 2;
        int B = -(r1 + 1) + (l2 - 1) + 1;
        int A = n - C - B, ty = (B+C)%2; 

        bool fe = 0; 
        if(is(max(0, B-C), min(A, B+C), ty)) fe = 1; 
        if(is(max(0, B-C-1), min(A, B+C-1), 1-ty)) fe = 1; 
        if(fe) ans = max(ans, C);    
    }
    return ans; 
}
int sequence(int Ni, vector<int> A) {
    n = Ni; 

    if(n <= 2000) return subtask_2(A); 
    
    int maxi = 0; 
    for(int x: A) maxi = max(maxi, x); 

    if(maxi <= 3) return subtask_4(A); 
    return subtask_3(A); 
}
# Verdict Execution time Memory Grader output
1 Correct 6 ms 11988 KB Output is correct
2 Correct 6 ms 12004 KB Output is correct
3 Correct 5 ms 12020 KB Output is correct
4 Correct 6 ms 11988 KB Output is correct
5 Correct 6 ms 11988 KB Output is correct
6 Correct 6 ms 11988 KB Output is correct
7 Correct 6 ms 11988 KB Output is correct
8 Correct 6 ms 11988 KB Output is correct
9 Correct 6 ms 11988 KB Output is correct
10 Correct 6 ms 11988 KB Output is correct
11 Correct 6 ms 11988 KB Output is correct
12 Correct 5 ms 11988 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 6 ms 11988 KB Output is correct
2 Correct 6 ms 12004 KB Output is correct
3 Correct 5 ms 12020 KB Output is correct
4 Correct 6 ms 11988 KB Output is correct
5 Correct 6 ms 11988 KB Output is correct
6 Correct 6 ms 11988 KB Output is correct
7 Correct 6 ms 11988 KB Output is correct
8 Correct 6 ms 11988 KB Output is correct
9 Correct 6 ms 11988 KB Output is correct
10 Correct 6 ms 11988 KB Output is correct
11 Correct 6 ms 11988 KB Output is correct
12 Correct 5 ms 11988 KB Output is correct
13 Correct 255 ms 12104 KB Output is correct
14 Correct 263 ms 12132 KB Output is correct
15 Correct 208 ms 12096 KB Output is correct
16 Correct 201 ms 12092 KB Output is correct
17 Correct 217 ms 12096 KB Output is correct
18 Correct 306 ms 12116 KB Output is correct
19 Correct 265 ms 12104 KB Output is correct
20 Correct 210 ms 12116 KB Output is correct
21 Correct 260 ms 12116 KB Output is correct
22 Correct 261 ms 12104 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 6 ms 11988 KB Output is correct
2 Incorrect 60 ms 27724 KB Output isn't correct
3 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 6 ms 12004 KB Output is correct
2 Correct 36 ms 17852 KB Output is correct
3 Correct 54 ms 22516 KB Output is correct
4 Correct 36 ms 17868 KB Output is correct
5 Correct 37 ms 17852 KB Output is correct
6 Correct 59 ms 24168 KB Output is correct
# Verdict Execution time Memory Grader output
1 Incorrect 85 ms 33468 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 6 ms 11988 KB Output is correct
2 Correct 6 ms 12004 KB Output is correct
3 Correct 5 ms 12020 KB Output is correct
4 Correct 6 ms 11988 KB Output is correct
5 Correct 6 ms 11988 KB Output is correct
6 Correct 6 ms 11988 KB Output is correct
7 Correct 6 ms 11988 KB Output is correct
8 Correct 6 ms 11988 KB Output is correct
9 Correct 6 ms 11988 KB Output is correct
10 Correct 6 ms 11988 KB Output is correct
11 Correct 6 ms 11988 KB Output is correct
12 Correct 5 ms 11988 KB Output is correct
13 Correct 255 ms 12104 KB Output is correct
14 Correct 263 ms 12132 KB Output is correct
15 Correct 208 ms 12096 KB Output is correct
16 Correct 201 ms 12092 KB Output is correct
17 Correct 217 ms 12096 KB Output is correct
18 Correct 306 ms 12116 KB Output is correct
19 Correct 265 ms 12104 KB Output is correct
20 Correct 210 ms 12116 KB Output is correct
21 Correct 260 ms 12116 KB Output is correct
22 Correct 261 ms 12104 KB Output is correct
23 Incorrect 17 ms 14676 KB Output isn't correct
24 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 6 ms 11988 KB Output is correct
2 Correct 6 ms 12004 KB Output is correct
3 Correct 5 ms 12020 KB Output is correct
4 Correct 6 ms 11988 KB Output is correct
5 Correct 6 ms 11988 KB Output is correct
6 Correct 6 ms 11988 KB Output is correct
7 Correct 6 ms 11988 KB Output is correct
8 Correct 6 ms 11988 KB Output is correct
9 Correct 6 ms 11988 KB Output is correct
10 Correct 6 ms 11988 KB Output is correct
11 Correct 6 ms 11988 KB Output is correct
12 Correct 5 ms 11988 KB Output is correct
13 Correct 255 ms 12104 KB Output is correct
14 Correct 263 ms 12132 KB Output is correct
15 Correct 208 ms 12096 KB Output is correct
16 Correct 201 ms 12092 KB Output is correct
17 Correct 217 ms 12096 KB Output is correct
18 Correct 306 ms 12116 KB Output is correct
19 Correct 265 ms 12104 KB Output is correct
20 Correct 210 ms 12116 KB Output is correct
21 Correct 260 ms 12116 KB Output is correct
22 Correct 261 ms 12104 KB Output is correct
23 Incorrect 60 ms 27724 KB Output isn't correct
24 Halted 0 ms 0 KB -