#include <bits/stdc++.h>
using namespace std;
const int N = 5e3 + 5, INF = 1e9 + 5;
int n, q, canmove[N][N];
struct Event{
int l, r;
bool operator < (const Event &sc) const{
if(r == sc.r) return l < sc.l;
else return r < sc.r;
}
};
Event arr[N];
vector<pair<Event, int>> v;
struct SegTree{
int tree[N * 8];
SegTree(){
fill(tree, tree + N * 4, INF);
}
int merge(int a, int b){
return min(a, b);
}
int query(int l, int r, int v = 1, int tl = 1, int tr = N - 1){
if(l > r) return INF;
else if(l == tl && r == tr) return tree[v];
else{
int tm = tl + (tr - tl) / 2;
return merge(query(l, min(tm, r), v * 2, tl, tm), query(max(tm + 1, l), r, v * 2 + 1, tm + 1, tr));
}
}
void update(int pos, int val, int v = 1, int l = 1, int r = N - 1){
if(l == r) tree[v] = min(tree[v], val);
else{
int m = l + (r - l) / 2;
if(pos <= m) update(pos, val, v * 2, l, m);
else update(pos, val, v * 2 + 1, m + 1, r);
tree[v] = merge(tree[v * 2], tree[v * 2 + 1]);
}
}
};
map<int, int> cmprs;
int main(){
ios_base::sync_with_stdio(false);cin.tie(NULL);
for(int i = 0; i < N; i++){
for(int j = 0; j < N; j++){
canmove[i][j] = INF;
}
}
cin >> n >> q;
for(int i = 1; i <= n; i++) cin >> arr[i].l >> arr[i].r;
for(int i = 1; i <= n; i++) cmprs[arr[i].l] = cmprs[arr[i].r] = 1;
int tmp = 0;
for(auto &p : cmprs) p.second = ++tmp;
for(int i = 1; i <= n; i++) arr[i].l = cmprs[arr[i].l], arr[i].r = cmprs[arr[i].r];
for(int i = 1; i <= n; i++) v.push_back({arr[i], i});
sort(v.begin(), v.end());
map<int, vector<int>> mp;
for(int i = 1; i <= n; i++) mp[arr[i].r].push_back(i);
for(auto p : mp){
for(auto x : p.second){
for(auto y : p.second){
canmove[x][y] = 1;
}
}
}
for(int i = 1; i <= n; i++){
canmove[i][i] = 0;
}
for(int i = 1; i <= n; i++){
SegTree sgt = SegTree();
for(auto p : v){
canmove[p.second][i] = min(canmove[p.second][i], sgt.query(p.first.l, p.first.r) + 1);
sgt.update(p.first.r, canmove[p.second][i]);
}
}
while(q--){
int s, e;
cin >> s >> e;
if(canmove[e][s] == INF) cout << "impossible\n";
else cout << canmove[e][s] << "\n";
}
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
48 ms |
98448 KB |
Output is correct |
2 |
Runtime error |
321 ms |
233708 KB |
Execution killed with signal 11 |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
46 ms |
98388 KB |
Output is correct |
2 |
Correct |
58 ms |
98396 KB |
Output is correct |
3 |
Correct |
189 ms |
98800 KB |
Output is correct |
4 |
Correct |
191 ms |
98816 KB |
Output is correct |
5 |
Correct |
179 ms |
98688 KB |
Output is correct |
6 |
Correct |
200 ms |
98764 KB |
Output is correct |
7 |
Correct |
289 ms |
98728 KB |
Output is correct |
8 |
Correct |
260 ms |
98748 KB |
Output is correct |
9 |
Correct |
146 ms |
98552 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
46 ms |
98388 KB |
Output is correct |
2 |
Correct |
58 ms |
98396 KB |
Output is correct |
3 |
Correct |
189 ms |
98800 KB |
Output is correct |
4 |
Correct |
191 ms |
98816 KB |
Output is correct |
5 |
Correct |
179 ms |
98688 KB |
Output is correct |
6 |
Correct |
200 ms |
98764 KB |
Output is correct |
7 |
Correct |
289 ms |
98728 KB |
Output is correct |
8 |
Correct |
260 ms |
98748 KB |
Output is correct |
9 |
Correct |
146 ms |
98552 KB |
Output is correct |
10 |
Correct |
55 ms |
98508 KB |
Output is correct |
11 |
Correct |
47 ms |
98472 KB |
Output is correct |
12 |
Correct |
210 ms |
98700 KB |
Output is correct |
13 |
Correct |
201 ms |
98700 KB |
Output is correct |
14 |
Correct |
191 ms |
98684 KB |
Output is correct |
15 |
Correct |
199 ms |
98644 KB |
Output is correct |
16 |
Correct |
287 ms |
98748 KB |
Output is correct |
17 |
Correct |
270 ms |
98752 KB |
Output is correct |
18 |
Correct |
136 ms |
98548 KB |
Output is correct |
19 |
Runtime error |
286 ms |
524288 KB |
Execution killed with signal 9 |
20 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
46 ms |
98388 KB |
Output is correct |
2 |
Correct |
58 ms |
98396 KB |
Output is correct |
3 |
Correct |
189 ms |
98800 KB |
Output is correct |
4 |
Correct |
191 ms |
98816 KB |
Output is correct |
5 |
Correct |
179 ms |
98688 KB |
Output is correct |
6 |
Correct |
200 ms |
98764 KB |
Output is correct |
7 |
Correct |
289 ms |
98728 KB |
Output is correct |
8 |
Correct |
260 ms |
98748 KB |
Output is correct |
9 |
Correct |
146 ms |
98552 KB |
Output is correct |
10 |
Correct |
50 ms |
98508 KB |
Output is correct |
11 |
Correct |
51 ms |
98504 KB |
Output is correct |
12 |
Correct |
242 ms |
98668 KB |
Output is correct |
13 |
Correct |
183 ms |
98640 KB |
Output is correct |
14 |
Correct |
187 ms |
98684 KB |
Output is correct |
15 |
Correct |
245 ms |
98640 KB |
Output is correct |
16 |
Correct |
286 ms |
98840 KB |
Output is correct |
17 |
Correct |
268 ms |
98636 KB |
Output is correct |
18 |
Correct |
157 ms |
98432 KB |
Output is correct |
19 |
Runtime error |
408 ms |
234000 KB |
Execution killed with signal 11 |
20 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
379 ms |
233888 KB |
Execution killed with signal 11 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
48 ms |
98448 KB |
Output is correct |
2 |
Runtime error |
321 ms |
233708 KB |
Execution killed with signal 11 |
3 |
Halted |
0 ms |
0 KB |
- |