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Submission #1047440

# Submission time Handle Problem Language Result Execution time Memory
1047440 2024-08-07T13:06:09 Z sofijavelkovska Event Hopping (BOI22_events) C++17
25 / 100
 1268 ms 100616 KB 
#include <bits/stdc++.h>
using namespace std;

const int MAXN=5e3, INF=1e9;

int n;
int l[MAXN], r[MAXN];

bool rcompare(int x, int y)
{
    if (r[x]==r[y])
        return l[x]<l[y];

    return r[x]<r[y];
}

bool lcompare(int x, int y)
{
    if (l[x]<l[y])
        return true;

    return false;
}

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    int q;
    cin >> n >> q;
    for (int i=0; i<n; i++)
        cin >> l[i] >> r[i];
    int sorted[n];
    for (int i=0; i<n; i++)
        sorted[i]=i;
    sort(sorted, sorted+n, rcompare);
    int ranked[n];
    for (int i=0; i<n; i++)
        ranked[sorted[i]]=i;
    map<int, int> compress;
    for (int i=0; i<n; i++)
    {
        compress[l[i]]=0;
        compress[r[i]]=0;
    }
    int counter=0;
    for (auto x : compress)
    {
        compress[x.first]=counter;
        counter=counter+1;
    }
    int lsorted[n];
    for (int i=0; i<n; i++)
        lsorted[i]=i;
    sort(lsorted, lsorted+n, lcompare);
    int answer[n][n];
    for (int i=0; i<n; i++)
        for (int j=0; j<n; j++)
        {
            if (i==j)
                answer[i][j]=0;
            else if (r[i]==r[j])
                answer[i][j]=1;
            else
                answer[i][j]=-1;
        }
    for (int y=0; y<n; y++)
    {
        int dp[n];
        dp[ranked[y]]=0;
        multiset<int> best;
        best.insert(0);
        //update(0, 0, MAXN, compress[l[y]], 0);
        int t=n-1;
        for (int i=ranked[y]-1; i>=0; i--)
        {
            while (t>=0 && l[lsorted[t]]>r[sorted[i]])
            {
                if (ranked[lsorted[t]]<=ranked[y] && dp[ranked[lsorted[t]]]!=INF)
                    best.erase(best.find(dp[ranked[lsorted[t]]]));
                t=t-1;
            }
            dp[i]=INF;
            if (!best.empty())
                dp[i]=*best.begin()+1;
            if (dp[i]!=INF)
                best.insert(dp[i]);
            if (dp[i]!=INF)
                answer[sorted[i]][y]=dp[i];
            //cout << "l r " << l[sorted[i]] << ' ' << r[sorted[i]] << '\n';
            //cout << "find " << find(0, 0, MAXN, 0, compress[r[sorted[i]]]+1) << '\n';
            //update(0, 0, MAXN, compress[l[sorted[i]]], dp[i]);
            //cout << "dp " << dp[i] << '\n';
        }
    }
    //for (int i=0; i<n; i++)
      //  for (int j=0; j<n; j++)
        //    cout << i+1 << ' ' << j+1 << ' ' << answer[i][j] << '\n';
    while (q--)
    {
        int x, y;
        cin >> x >> y;
        x=x-1;
        y=y-1;
        if (answer[x][y]!=-1)
            cout << answer[x][y] << '\n';
        else
            cout << "impossible" << '\n';
    }

    return 0;
}



/*#include <bits/stdc++.h>
using namespace std;

const int MAXN=1e5, LOG=17;

int n;
int l[MAXN], r[MAXN];

bool rcompare(int x, int y)
{
    if (r[x]<r[y])
        return true;

    return false;
}

bool lcompare(int x, int y)
{
    if (l[x]<l[y])
        return true;

    return false;
}

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    int q;
    cin >> n >> q;
    for (int i=0; i<n; i++)
        cin >> l[i] >> r[i];
    int sorted[n];
    for (int i=0; i<n; i++)
        sorted[i]=i;
    sort(sorted, sorted+n, rcompare);
    int ranked[n];
    for (int i=0; i<n; i++)
        ranked[sorted[i]]=i;
    int lsorted[n];
    for (int i=0; i<n; i++)
        lsorted[i]=i;
    sort(lsorted, lsorted+n, lcompare);
    int t=n-1;
    set<int> farthest;
    for (int i=0; i<n; i++)
        farthest.insert(i);
    int blift[n][LOG];
    for (int i=0; i<n; i++)
        for (int j=0; j<LOG; j++)
            blift[i][j]=-1;
    for (int i=n-1; i>=0; i--)
    {
        while (t>=0 && l[lsorted[t]]>r[sorted[i]])
        {
            farthest.erase(ranked[lsorted[t]]);
            t=t-1;
        }
        auto it=farthest.end();
        it--;
        if (*it!=i)
            blift[i][0]=*it;
    }
    for (int j=1; j<LOG; j++)
        for (int i=0; i<n; i++)
            if (blift[i][j-1]!=-1 && blift[blift[i][j-1]][j-1]!=-1)
                blift[i][j]=blift[blift[i][j-1]][j-1];
    while (q--)
    {
        int x, y;
        cin >> x >> y;
        x=ranked[x-1];
        y=ranked[y-1];
        if (x>y)
        {
            cout << "impossible" << '\n';
            continue;
        }
        if (x==y)
        {
            cout << 0 << '\n';
            continue;
        }
        int total=0;
        for (int j=LOG-1; j>=0; j--)
        {
            if (blift[x][j]!=-1 && blift[x][j]<y)
            {
                x=blift[x][j];
                total=total+(1<<j);
            }
        }
        if (blift[x][0]>=y)
            cout << total+1 << '\n';
        else
            cout << "impossible" << '\n';
    }

    return 0;
}*/

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Runtime error 1 ms 604 KB Execution killed with signal 11
3 Halted 0 ms 0 KB -

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 13 ms 4444 KB Output is correct
4 Correct 9 ms 4444 KB Output is correct
5 Correct 13 ms 4444 KB Output is correct
6 Correct 26 ms 4696 KB Output is correct
7 Correct 45 ms 4444 KB Output is correct
8 Correct 23 ms 4444 KB Output is correct
9 Correct 22 ms 4188 KB Output is correct

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 13 ms 4444 KB Output is correct
4 Correct 9 ms 4444 KB Output is correct
5 Correct 13 ms 4444 KB Output is correct
6 Correct 26 ms 4696 KB Output is correct
7 Correct 45 ms 4444 KB Output is correct
8 Correct 23 ms 4444 KB Output is correct
9 Correct 22 ms 4188 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 13 ms 4444 KB Output is correct
13 Correct 9 ms 4440 KB Output is correct
14 Correct 17 ms 4444 KB Output is correct
15 Correct 25 ms 4452 KB Output is correct
16 Correct 46 ms 4444 KB Output is correct
17 Correct 22 ms 4440 KB Output is correct
18 Correct 21 ms 4444 KB Output is correct
19 Correct 721 ms 99924 KB Output is correct
20 Correct 465 ms 99924 KB Output is correct
21 Correct 505 ms 100176 KB Output is correct
22 Correct 765 ms 100456 KB Output is correct
23 Correct 1268 ms 100436 KB Output is correct
24 Correct 726 ms 100616 KB Output is correct
25 Correct 659 ms 100064 KB Output is correct

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 13 ms 4444 KB Output is correct
4 Correct 9 ms 4444 KB Output is correct
5 Correct 13 ms 4444 KB Output is correct
6 Correct 26 ms 4696 KB Output is correct
7 Correct 45 ms 4444 KB Output is correct
8 Correct 23 ms 4444 KB Output is correct
9 Correct 22 ms 4188 KB Output is correct
10 Correct 0 ms 344 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 13 ms 4444 KB Output is correct
13 Correct 9 ms 4440 KB Output is correct
14 Correct 13 ms 4444 KB Output is correct
15 Correct 25 ms 4444 KB Output is correct
16 Correct 45 ms 4444 KB Output is correct
17 Correct 22 ms 4440 KB Output is correct
18 Correct 26 ms 4440 KB Output is correct
19 Runtime error 1 ms 604 KB Execution killed with signal 11
20 Halted 0 ms 0 KB -

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Runtime error 1 ms 604 KB Execution killed with signal 11
2 Halted 0 ms 0 KB -

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Runtime error 1 ms 604 KB Execution killed with signal 11
3 Halted 0 ms 0 KB -