#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pb(x) push_back(x)
#define mp(x,y) make_pair(x,y)
#define all(x) x.begin(),x.end()
#define vf first
#define vs second
const int mod = 998244353;
const int MX = 1000000005;
const int L = 20;
struct Seg {
int siz;
vector<pair<int,int>> v;
void init(int n){
siz = 1;
while(siz < n)siz *= 2;
v.assign(siz*2,mp(MX,-1));
}
pair<int,int> merge(pair<int,int> x , pair<int,int> y){
pair<int,int> res;
res.vf = min(x.vf , y.vf);
if(x.vf == y.vf)res.vs = min(x.vs , y.vs);
else if(res.vf == x.vf)res.vs = x.vs;
else res.vs = y.vs;
return res;
}
void set(int i , pair<int,int> p , int x , int lx , int rx){
if(rx - lx == 1){
v[x] = merge(p,v[x]);
return;
}
int m = (lx + rx)/2;
if(i < m)
set(i , p , 2 * x + 1 , lx , m);
else
set(i , p , 2 * x + 2 , m , rx);
v[x] = merge(v[2 * x + 1] , v[2 * x + 2]);
}
void set(int i , pair<int,int> p){
set(i , p , 0 , 0 , siz);
}
pair<int,int> range_mx(int l , int r , int x , int lx , int rx){
if(l >= rx || lx >= r)return mp(MX,-1);
if(lx >= l && rx <= r)return v[x];
int m = (lx + rx)/2;
return merge(range_mx(l,r,2*x+1,lx,m),range_mx(l,r,2*x+2,m,rx));
}
pair<int,int> range_mx(int l , int r){
return range_mx(l , r , 0 , 0 , siz);
}
};
void solve(){
int n , q;
cin >> n >> q;
vector<pair<int,int>> v(n);
for(int i = 0; i < n; i++){
cin >> v[i].vf >> v[i].vs;
}
// positions acocrding to sorted e
vector<pair<int,pair<int,int>>> e_sort;
//vector<pair<int,pair<int,int>>> rev;
for(int i = 0; i < n; i++){
e_sort.pb(mp(v[i].vs , mp(v[i].vf,i)));
}
sort(all(e_sort));
//rev = e_sort;
//reverse(all(rev));
int pos[n],rev[n];
for(int i = 0; i < n; i++){
pos[e_sort[i].vs.vs] = i;
rev[i] = e_sort[i].vs.vs;
}
// segtree
Seg st;
st.init(n + 1);
for(int i = n - 1; i >= 0; i--){
st.set(i,mp(e_sort[i].vs.vf , i));
}
// binary lifting
int up[n][L];
int p[n];
for(int i = 0; i < n; i++){
pair<int,pair<int,int>> tp = mp(e_sort[i].vs.vf , mp(-1 , -1));
int left = (lower_bound(all(e_sort),tp) - e_sort.begin());
if(left == i)
up[i][0] = p[i] = i;
else {
p[i] = st.range_mx(left,i).vs;
//cout << left << ' ' << st.range_mx(left,i).vf << ' ' << p[i] << '\n';
up[i][0] = p[i];
}
}
for(int j = 1; j < L; j++){
for(int i = 0; i < n; i++){
if(j == 1)
up[i][j] = up[p[i]][j-1];
else
up[i][j] = up[up[i][j-1]][j-1];
}
}
// answering the queries
while(q--){
int s , e;
cin >> s >> e;
s--;
e--;
if(s == e){
cout << 0 << '\n';
continue;
}
int ogs = pos[s] , oge = pos[e];
if(ogs > oge){
if(v[s].vs >= v[e].vf && v[s].vs <= v[e].vs){
cout << 1 << '\n';
continue;
}
else {
cout << "impossible\n";
continue;
}
}
int i = oge;
int mn = v[s].vs;
int ans = 0;
for(int j = L-1; j >= 0; j--){
if(v[rev[up[i][j]]].vf > mn){
ans += (1<<j);
i = up[i][j];
}
}
if(v[rev[i]].vf > mn){
i = up[i][0];
ans++;
}
ans++;
i = up[i][0];
if(v[rev[i]].vf > mn)
cout << "impossible\n";
else
cout << ans << "\n";
}
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
//int t;cin >> t;
//while(t--)
solve();
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
78 ms |
17256 KB |
Output is correct |
3 |
Correct |
80 ms |
17096 KB |
Output is correct |
4 |
Correct |
91 ms |
17088 KB |
Output is correct |
5 |
Correct |
82 ms |
17208 KB |
Output is correct |
6 |
Correct |
80 ms |
17520 KB |
Output is correct |
7 |
Correct |
80 ms |
17348 KB |
Output is correct |
8 |
Correct |
67 ms |
17772 KB |
Output is correct |
9 |
Correct |
74 ms |
17708 KB |
Output is correct |
10 |
Correct |
95 ms |
17776 KB |
Output is correct |
11 |
Correct |
96 ms |
17584 KB |
Output is correct |
12 |
Correct |
63 ms |
16840 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
344 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
1 ms |
604 KB |
Output is correct |
4 |
Correct |
1 ms |
600 KB |
Output is correct |
5 |
Correct |
1 ms |
344 KB |
Output is correct |
6 |
Correct |
1 ms |
604 KB |
Output is correct |
7 |
Correct |
1 ms |
604 KB |
Output is correct |
8 |
Correct |
1 ms |
856 KB |
Output is correct |
9 |
Correct |
1 ms |
604 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
344 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
1 ms |
604 KB |
Output is correct |
4 |
Correct |
1 ms |
600 KB |
Output is correct |
5 |
Correct |
1 ms |
344 KB |
Output is correct |
6 |
Correct |
1 ms |
604 KB |
Output is correct |
7 |
Correct |
1 ms |
604 KB |
Output is correct |
8 |
Correct |
1 ms |
856 KB |
Output is correct |
9 |
Correct |
1 ms |
604 KB |
Output is correct |
10 |
Correct |
1 ms |
348 KB |
Output is correct |
11 |
Correct |
0 ms |
452 KB |
Output is correct |
12 |
Correct |
1 ms |
604 KB |
Output is correct |
13 |
Correct |
1 ms |
604 KB |
Output is correct |
14 |
Correct |
1 ms |
348 KB |
Output is correct |
15 |
Correct |
1 ms |
604 KB |
Output is correct |
16 |
Correct |
1 ms |
600 KB |
Output is correct |
17 |
Correct |
1 ms |
500 KB |
Output is correct |
18 |
Correct |
1 ms |
604 KB |
Output is correct |
19 |
Correct |
27 ms |
2484 KB |
Output is correct |
20 |
Correct |
25 ms |
2652 KB |
Output is correct |
21 |
Correct |
27 ms |
2964 KB |
Output is correct |
22 |
Correct |
26 ms |
2904 KB |
Output is correct |
23 |
Correct |
26 ms |
2904 KB |
Output is correct |
24 |
Correct |
19 ms |
2912 KB |
Output is correct |
25 |
Correct |
23 ms |
2392 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
344 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
1 ms |
604 KB |
Output is correct |
4 |
Correct |
1 ms |
600 KB |
Output is correct |
5 |
Correct |
1 ms |
344 KB |
Output is correct |
6 |
Correct |
1 ms |
604 KB |
Output is correct |
7 |
Correct |
1 ms |
604 KB |
Output is correct |
8 |
Correct |
1 ms |
856 KB |
Output is correct |
9 |
Correct |
1 ms |
604 KB |
Output is correct |
10 |
Correct |
0 ms |
348 KB |
Output is correct |
11 |
Correct |
0 ms |
348 KB |
Output is correct |
12 |
Correct |
1 ms |
604 KB |
Output is correct |
13 |
Correct |
1 ms |
604 KB |
Output is correct |
14 |
Correct |
1 ms |
600 KB |
Output is correct |
15 |
Correct |
1 ms |
604 KB |
Output is correct |
16 |
Correct |
1 ms |
604 KB |
Output is correct |
17 |
Correct |
1 ms |
604 KB |
Output is correct |
18 |
Correct |
1 ms |
604 KB |
Output is correct |
19 |
Correct |
58 ms |
15548 KB |
Output is correct |
20 |
Correct |
53 ms |
14720 KB |
Output is correct |
21 |
Correct |
62 ms |
15296 KB |
Output is correct |
22 |
Correct |
53 ms |
15304 KB |
Output is correct |
23 |
Correct |
50 ms |
15488 KB |
Output is correct |
24 |
Correct |
64 ms |
15280 KB |
Output is correct |
25 |
Correct |
43 ms |
14844 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
80 ms |
17288 KB |
Output is correct |
2 |
Correct |
79 ms |
17216 KB |
Output is correct |
3 |
Correct |
87 ms |
17260 KB |
Output is correct |
4 |
Correct |
69 ms |
17608 KB |
Output is correct |
5 |
Correct |
88 ms |
17608 KB |
Output is correct |
6 |
Correct |
98 ms |
17280 KB |
Output is correct |
7 |
Correct |
120 ms |
17188 KB |
Output is correct |
8 |
Correct |
86 ms |
17348 KB |
Output is correct |
9 |
Correct |
52 ms |
15304 KB |
Output is correct |
10 |
Correct |
84 ms |
17000 KB |
Output is correct |
11 |
Correct |
95 ms |
17028 KB |
Output is correct |
12 |
Correct |
85 ms |
17088 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
78 ms |
17256 KB |
Output is correct |
3 |
Correct |
80 ms |
17096 KB |
Output is correct |
4 |
Correct |
91 ms |
17088 KB |
Output is correct |
5 |
Correct |
82 ms |
17208 KB |
Output is correct |
6 |
Correct |
80 ms |
17520 KB |
Output is correct |
7 |
Correct |
80 ms |
17348 KB |
Output is correct |
8 |
Correct |
67 ms |
17772 KB |
Output is correct |
9 |
Correct |
74 ms |
17708 KB |
Output is correct |
10 |
Correct |
95 ms |
17776 KB |
Output is correct |
11 |
Correct |
96 ms |
17584 KB |
Output is correct |
12 |
Correct |
63 ms |
16840 KB |
Output is correct |
13 |
Correct |
1 ms |
344 KB |
Output is correct |
14 |
Correct |
0 ms |
348 KB |
Output is correct |
15 |
Correct |
1 ms |
604 KB |
Output is correct |
16 |
Correct |
1 ms |
600 KB |
Output is correct |
17 |
Correct |
1 ms |
344 KB |
Output is correct |
18 |
Correct |
1 ms |
604 KB |
Output is correct |
19 |
Correct |
1 ms |
604 KB |
Output is correct |
20 |
Correct |
1 ms |
856 KB |
Output is correct |
21 |
Correct |
1 ms |
604 KB |
Output is correct |
22 |
Correct |
1 ms |
348 KB |
Output is correct |
23 |
Correct |
0 ms |
452 KB |
Output is correct |
24 |
Correct |
1 ms |
604 KB |
Output is correct |
25 |
Correct |
1 ms |
604 KB |
Output is correct |
26 |
Correct |
1 ms |
348 KB |
Output is correct |
27 |
Correct |
1 ms |
604 KB |
Output is correct |
28 |
Correct |
1 ms |
600 KB |
Output is correct |
29 |
Correct |
1 ms |
500 KB |
Output is correct |
30 |
Correct |
1 ms |
604 KB |
Output is correct |
31 |
Correct |
27 ms |
2484 KB |
Output is correct |
32 |
Correct |
25 ms |
2652 KB |
Output is correct |
33 |
Correct |
27 ms |
2964 KB |
Output is correct |
34 |
Correct |
26 ms |
2904 KB |
Output is correct |
35 |
Correct |
26 ms |
2904 KB |
Output is correct |
36 |
Correct |
19 ms |
2912 KB |
Output is correct |
37 |
Correct |
23 ms |
2392 KB |
Output is correct |
38 |
Correct |
0 ms |
348 KB |
Output is correct |
39 |
Correct |
0 ms |
348 KB |
Output is correct |
40 |
Correct |
1 ms |
604 KB |
Output is correct |
41 |
Correct |
1 ms |
604 KB |
Output is correct |
42 |
Correct |
1 ms |
600 KB |
Output is correct |
43 |
Correct |
1 ms |
604 KB |
Output is correct |
44 |
Correct |
1 ms |
604 KB |
Output is correct |
45 |
Correct |
1 ms |
604 KB |
Output is correct |
46 |
Correct |
1 ms |
604 KB |
Output is correct |
47 |
Correct |
58 ms |
15548 KB |
Output is correct |
48 |
Correct |
53 ms |
14720 KB |
Output is correct |
49 |
Correct |
62 ms |
15296 KB |
Output is correct |
50 |
Correct |
53 ms |
15304 KB |
Output is correct |
51 |
Correct |
50 ms |
15488 KB |
Output is correct |
52 |
Correct |
64 ms |
15280 KB |
Output is correct |
53 |
Correct |
43 ms |
14844 KB |
Output is correct |
54 |
Correct |
80 ms |
17288 KB |
Output is correct |
55 |
Correct |
79 ms |
17216 KB |
Output is correct |
56 |
Correct |
87 ms |
17260 KB |
Output is correct |
57 |
Correct |
69 ms |
17608 KB |
Output is correct |
58 |
Correct |
88 ms |
17608 KB |
Output is correct |
59 |
Correct |
98 ms |
17280 KB |
Output is correct |
60 |
Correct |
120 ms |
17188 KB |
Output is correct |
61 |
Correct |
86 ms |
17348 KB |
Output is correct |
62 |
Correct |
52 ms |
15304 KB |
Output is correct |
63 |
Correct |
84 ms |
17000 KB |
Output is correct |
64 |
Correct |
95 ms |
17028 KB |
Output is correct |
65 |
Correct |
85 ms |
17088 KB |
Output is correct |
66 |
Correct |
0 ms |
348 KB |
Output is correct |
67 |
Correct |
78 ms |
17252 KB |
Output is correct |
68 |
Correct |
78 ms |
17208 KB |
Output is correct |
69 |
Correct |
87 ms |
17076 KB |
Output is correct |
70 |
Correct |
80 ms |
17284 KB |
Output is correct |
71 |
Correct |
80 ms |
17332 KB |
Output is correct |
72 |
Correct |
78 ms |
17352 KB |
Output is correct |
73 |
Correct |
69 ms |
17856 KB |
Output is correct |
74 |
Correct |
68 ms |
17544 KB |
Output is correct |
75 |
Correct |
90 ms |
17604 KB |
Output is correct |
76 |
Correct |
83 ms |
17612 KB |
Output is correct |
77 |
Correct |
67 ms |
16792 KB |
Output is correct |
78 |
Correct |
0 ms |
348 KB |
Output is correct |
79 |
Correct |
1 ms |
604 KB |
Output is correct |
80 |
Correct |
1 ms |
604 KB |
Output is correct |
81 |
Correct |
1 ms |
464 KB |
Output is correct |
82 |
Correct |
1 ms |
604 KB |
Output is correct |
83 |
Correct |
1 ms |
604 KB |
Output is correct |
84 |
Correct |
1 ms |
604 KB |
Output is correct |
85 |
Correct |
1 ms |
604 KB |
Output is correct |
86 |
Correct |
27 ms |
2696 KB |
Output is correct |
87 |
Correct |
26 ms |
2904 KB |
Output is correct |
88 |
Correct |
29 ms |
2896 KB |
Output is correct |
89 |
Correct |
21 ms |
2908 KB |
Output is correct |
90 |
Correct |
20 ms |
2896 KB |
Output is correct |
91 |
Correct |
20 ms |
2908 KB |
Output is correct |
92 |
Correct |
22 ms |
2548 KB |
Output is correct |
93 |
Correct |
57 ms |
15300 KB |
Output is correct |
94 |
Correct |
54 ms |
14540 KB |
Output is correct |
95 |
Correct |
61 ms |
15232 KB |
Output is correct |
96 |
Correct |
54 ms |
15408 KB |
Output is correct |
97 |
Correct |
50 ms |
15456 KB |
Output is correct |
98 |
Correct |
62 ms |
15304 KB |
Output is correct |
99 |
Correct |
44 ms |
14800 KB |
Output is correct |
100 |
Correct |
99 ms |
17352 KB |
Output is correct |
101 |
Correct |
97 ms |
17324 KB |
Output is correct |
102 |
Correct |
94 ms |
17444 KB |
Output is correct |
103 |
Correct |
84 ms |
16832 KB |
Output is correct |
104 |
Correct |
81 ms |
16824 KB |
Output is correct |
105 |
Correct |
87 ms |
17000 KB |
Output is correct |
106 |
Correct |
105 ms |
16808 KB |
Output is correct |
107 |
Correct |
95 ms |
16744 KB |
Output is correct |
108 |
Correct |
87 ms |
17352 KB |
Output is correct |
109 |
Correct |
84 ms |
17416 KB |
Output is correct |
110 |
Correct |
112 ms |
17280 KB |
Output is correct |
111 |
Correct |
100 ms |
17284 KB |
Output is correct |