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답안 #1047418

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
1047418 2024-08-07T12:43:20 Z sofijavelkovska Event Hopping (BOI22_events) C++17
10 / 100
 1500 ms 11032 KB 
#include <bits/stdc++.h>
using namespace std;

const int MAXN=(1<<18), INF=1e9;

int n;
int l[MAXN], r[MAXN];
int tree[2*MAXN-1];

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

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

int find(int x, int l, int r, int lt, int rt)
{
    if (l>=rt || r<=lt)
        return INF;
    if (l>=lt && r<=rt)
        return tree[x];

    return min(find(2*x+1, l, (l+r)/2, lt, rt), find(2*x+2, (l+r)/2, r, lt, rt));
}

void update(int x, int l, int r, int index, int value)
{
    if (l>index || r<=index)
        return;
    if (r-l==1)
    {
        tree[x]=min(tree[x], value);
        return;
    }
    update(2*x+1, l, (l+r)/2, index, value);
    update(2*x+2, (l+r)/2, r, index, value);
    tree[x]=min(tree[2*x+1], tree[2*x+2]);

    return;
}

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;
    }
    while (q--)
    {
        int x, y;
        cin >> x >> y;
        x=x-1;
        y=y-1;
        if (x==y)
        {
            cout << 0 << '\n';
            continue;
        }
        if (r[x]>r[y])
        {
            cout << "impossible" << '\n';
            continue;
        }
        if (r[x]==r[y])
        {
            cout << 1 << '\n';
            continue;
        }
        for (int i=0; i<2*MAXN-1; i++)
            tree[i]=INF;
        int dp[n];
        dp[ranked[y]]=0;
        update(0, 0, MAXN, compress[l[y]], 0);
        for (int i=ranked[y]-1; i>=0; i--)
        {
            dp[i]=min(INF, find(0, 0, MAXN, 0, compress[r[sorted[i]]]+1)+1);
            //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';
        }
        if (dp[ranked[x]]!=INF)
            cout << dp[ranked[x]] << '\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

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 2652 KB Output is correct
2 Execution timed out 1590 ms 8988 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #2
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 2648 KB Output is correct
2 Correct 1 ms 2652 KB Output is correct
3 Correct 40 ms 2652 KB Output is correct
4 Correct 17 ms 2652 KB Output is correct
5 Correct 16 ms 2652 KB Output is correct
6 Correct 16 ms 2652 KB Output is correct
7 Correct 19 ms 2652 KB Output is correct
8 Correct 18 ms 2652 KB Output is correct
9 Correct 1 ms 2392 KB Output is correct

Subtask #3
0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 2648 KB Output is correct
2 Correct 1 ms 2652 KB Output is correct
3 Correct 40 ms 2652 KB Output is correct
4 Correct 17 ms 2652 KB Output is correct
5 Correct 16 ms 2652 KB Output is correct
6 Correct 16 ms 2652 KB Output is correct
7 Correct 19 ms 2652 KB Output is correct
8 Correct 18 ms 2652 KB Output is correct
9 Correct 1 ms 2392 KB Output is correct
10 Correct 1 ms 2652 KB Output is correct
11 Correct 1 ms 2652 KB Output is correct
12 Correct 39 ms 2652 KB Output is correct
13 Correct 16 ms 2652 KB Output is correct
14 Correct 18 ms 2652 KB Output is correct
15 Correct 17 ms 2652 KB Output is correct
16 Correct 19 ms 2652 KB Output is correct
17 Correct 17 ms 2652 KB Output is correct
18 Correct 1 ms 2396 KB Output is correct
19 Execution timed out 1589 ms 3280 KB Time limit exceeded
20 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 2648 KB Output is correct
2 Correct 1 ms 2652 KB Output is correct
3 Correct 40 ms 2652 KB Output is correct
4 Correct 17 ms 2652 KB Output is correct
5 Correct 16 ms 2652 KB Output is correct
6 Correct 16 ms 2652 KB Output is correct
7 Correct 19 ms 2652 KB Output is correct
8 Correct 18 ms 2652 KB Output is correct
9 Correct 1 ms 2392 KB Output is correct
10 Correct 1 ms 2648 KB Output is correct
11 Correct 1 ms 2652 KB Output is correct
12 Correct 41 ms 2652 KB Output is correct
13 Correct 19 ms 2648 KB Output is correct
14 Correct 16 ms 2652 KB Output is correct
15 Correct 15 ms 2648 KB Output is correct
16 Correct 19 ms 2652 KB Output is correct
17 Correct 16 ms 2652 KB Output is correct
18 Correct 1 ms 2396 KB Output is correct
19 Execution timed out 1598 ms 11032 KB Time limit exceeded
20 Halted 0 ms 0 KB -

Subtask #5
0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Execution timed out 1533 ms 9040 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #6
0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 2652 KB Output is correct
2 Execution timed out 1590 ms 8988 KB Time limit exceeded
3 Halted 0 ms 0 KB -