#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;
}*/
# |
결과 |
실행 시간 |
메모리 |
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 |
- |
# |
결과 |
실행 시간 |
메모리 |
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 |
# |
결과 |
실행 시간 |
메모리 |
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 |
# |
결과 |
실행 시간 |
메모리 |
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 |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
1 ms |
604 KB |
Execution killed with signal 11 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
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 |
- |