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Submission #1016807

# Submission time Handle Problem Language Result Execution time Memory
1016807 2024-07-08T12:44:10 Z GrindMachine Railway Trip (JOI17_railway_trip) C++17
20 / 100
 2000 ms 18360 KB 
#include <bits/stdc++.h>
 
using namespace std ;
 
// modified from: https://oj.uz/submission/825591
 
const int MAX = 1e5 + 10 ;
 
int arr[MAX] ;
int n , k , q ;
 
int L[MAX][20] , R[MAX][20] ;
 
int solve(int x , int y)
{
    int ans = 0;
    int l = x, r = x;
 
    while(true){
        int l2 = -1, r2 = -1;
        if(arr[l] > arr[r]){
            l2 = L[l][0], r2 = R[l][0];
        }
        else if(arr[l] < arr[r]){
            l2 = L[r][0], r2 = R[r][0];
        }
        else{
            l2 = L[l][0], r2 = R[r][0];
        }
 
        // int l2 = min(L[l][0],L[r][0]);
        // int r2 = max(R[l][0],R[r][0]);
        if(r2 >= y) break;
        l = l2, r = r2;
        ans++;
    }
    
    int oldl = l, oldr = r;
    x = r;
    l = r = y;
 
    while(true){
        int l2 = min(L[l][0],L[r][0]);
        int r2 = max(R[l][0],R[r][0]);
        if(l2 <= x) break;
        l = l2, r = r2;
        ans++;
    }
    
    int cnt = 0;

    for(auto x : {oldl,oldr}){
        for(auto y : {l,r}){
            if(R[x][0] == r or L[y][0] == x){
                cnt++;
            }
        }
    }

    assert(cnt);
    return ans;
 
    // int ans = 0 ;
    // int l = x , r = x ;
    // for(int i = 19 ; i >= 0 ; --i)
    // {
    //     if(max(R[l][i] , R[r][i]) < y)
    //     {
    //         ans += (1 << i)  ;
    //         int l2 = l , r2 = r ;
    //         l = min(L[l2][i] , L[r2][i]) ;
    //         r = max(R[l2][i] , R[r2][i]) ;
    //     }
    // }
    // x = r ;
    // l = r = y ;
    // for(int i = 19 ; i >= 0 ; --i)
    // {
    //     if(min(L[l][i] , L[r][i]) > x)
    //     {
    //         ans += (1 << i) ;
    //         int l2 = l , r2 = r ;
    //         l = min(L[l2][i] , L[r2][i]) ;
    //         r = max(R[l2][i] , R[r2][i]) ;
    //     }
    // }
    // return ans ;
}
 
int main()
{
    ios_base::sync_with_stdio(0) ;
    cin.tie(0) ;
    cin>>n>>k>>q ;
    for(int i = 1 ; i <= n ; ++i)
        cin>>arr[i] ;
    stack<int>s ;
    for(int i = 1 ; i <= n ; ++i)
    {
        L[i][0] = 1 ;
        while(s.size() && arr[i] > arr[s.top()])
            s.pop() ;
        if(s.size())
            L[i][0] = s.top() ;
        s.push(i) ;
    }
    while(s.size())
        s.pop() ;
    for(int i = n ; i >= 1 ; --i)
    {
        R[i][0] = n ;
        while(s.size() && arr[i] > arr[s.top()])
            s.pop() ;
        if(s.size())
            R[i][0] = s.top() ;
        s.push(i) ;
    }
    for(int j = 1 ; j < 20 ; ++j)
    {
        for(int i = 1 ; i <= n ; ++i)
        {
            // int x = L[i][j-1], y = R[i][j-1];
            // if(arr[x] < arr[y]) swap(x,y);
            // if(arr[x] >= arr[y]){
            //     L[i][j] = L[x][j-1];
            //     R[i][j] = R[x][j-1];
            // }
            L[i][j] = min(L[L[i][j-1]][j-1] , L[R[i][j-1]][j-1]) ; 
            R[i][j] = max(R[R[i][j-1]][j-1] , R[L[i][j-1]][j-1]) ;
        }
    }
    while(q--)
    {
        int x , y ;
        cin>>x>>y ;
        if(x > y)
            swap(x , y) ;
        cout<<solve(x , y)<<"\n" ;
    }
    return 0 ;
}

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2396 KB Output is correct
2 Correct 0 ms 2396 KB Output is correct
3 Correct 0 ms 2396 KB Output is correct
4 Correct 0 ms 2396 KB Output is correct
5 Correct 1 ms 2396 KB Output is correct
6 Correct 0 ms 2396 KB Output is correct
7 Correct 0 ms 2484 KB Output is correct
8 Correct 1 ms 2396 KB Output is correct
9 Correct 1 ms 2396 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2396 KB Output is correct
2 Correct 17 ms 16728 KB Output is correct
3 Correct 16 ms 16732 KB Output is correct
4 Correct 16 ms 16732 KB Output is correct
5 Correct 17 ms 16720 KB Output is correct
6 Correct 14 ms 16824 KB Output is correct
7 Correct 16 ms 16988 KB Output is correct
8 Correct 21 ms 17032 KB Output is correct
9 Correct 22 ms 17244 KB Output is correct
10 Correct 25 ms 16988 KB Output is correct
11 Correct 23 ms 17244 KB Output is correct
12 Correct 21 ms 17244 KB Output is correct
13 Correct 21 ms 17164 KB Output is correct
14 Correct 21 ms 17244 KB Output is correct
15 Correct 21 ms 17252 KB Output is correct
16 Correct 22 ms 16984 KB Output is correct
17 Correct 16 ms 16988 KB Output is correct
18 Correct 15 ms 16988 KB Output is correct
19 Correct 14 ms 17084 KB Output is correct

Subtask #3
0 / 25.0

# Verdict Execution time Memory Grader output
1 Execution timed out 2041 ms 18084 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #4
0 / 55.0

# Verdict Execution time Memory Grader output
1 Correct 54 ms 18256 KB Output is correct
2 Correct 49 ms 18260 KB Output is correct
3 Correct 51 ms 18360 KB Output is correct
4 Correct 55 ms 18260 KB Output is correct
5 Execution timed out 2073 ms 17596 KB Time limit exceeded
6 Halted 0 ms 0 KB -