#include <bits/stdc++.h>
#define fr(i, a, b) for (int i = (a); i <= (b); ++i)
#define rf(i, a, b) for (int i = (a); i >= (b); --i)
#define fe(x, y) for (auto& x : y)
#define fi first
#define se second
#define pb push_back
#define mp make_pair
#define mt make_tuple
#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()
#define pw(x) (1LL << (x))
using namespace std;
mt19937_64 rng(228);
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
template <typename T>
using oset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define fbo find_by_order
#define ook order_of_key
template <typename T>
bool umn(T& a, T b) {
return a > b ? a = b, 1 : 0;
}
template <typename T>
bool umx(T& a, T b) {
return a < b ? a = b, 1 : 0;
}
using ll = long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
template <typename T>
using ve = vector<T>;
const int N = 1e5 + 5;
int n, q;
pii a[N];
ve<int> order;
int to[N];
int d[N];
ve<pii> Q[N];
int ans[N];
//bool subtask1 = 1;
pii get(int v) {
if (to[v] == v) {
return {v, 0};
} else {
pii p = get(to[v]);
p.se += d[v];
to[v] = p.fi;
d[v] = p.se;
return {p.fi, p.se};
}
}
bool TL() {
return (double)clock() / CLOCKS_PER_SEC > 1.4;
}
ve<int> st;
bool have[N];
bool subtask = 1;
bool subtask1;
int go[N][20];
int main() {
#ifdef LOCAL
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#else
ios::sync_with_stdio(0);
cin.tie(0);
#endif
cin >> n >> q;
// subtask1 &= n > 5000 || q > 100;
ve<int> u;
fr (i, 1, n) {
cin >> a[i].fi >> a[i].se;
order.pb(i);
u.pb(a[i].se);
}
sort(all(u));
{
sort(all(order), [](int i, int j) {
return a[i].fi < a[j].fi || (a[i].fi == a[j].fi && a[i].se > a[j].se);
});
fe (i, order) {
if (sz(st) && a[st.back()].se >= a[i].se) {
to[i] = st.back();
continue;
}
st.pb(i);
have[i] = 1;
}
fr (i, 1, sz(st) - 1) {
assert(a[st[i]].fi > a[st[i - 1]].fi);
assert(a[st[i]].se > a[st[i - 1]].se);
}
{
int mx = -1e9;
int mxI = -1;
int ptr = 0;
fe (i, st) {
while (ptr < sz(st) && a[st[ptr]].fi <= a[i].se) {
if (umx(mx, a[st[ptr]].se)) {
mxI = st[ptr];
}
ptr++;
}
if (mx >= a[i].se) {
to[i] = mxI;
} else {
assert(0);
to[i] = -1;
}
}
}
subtask &= sz(st) == n;
}
if (subtask) {
fr (i, 1, n) {
go[i][0] = to[i];
}
fr (p, 1, 19) {
fr (i, 1, n) {
go[i][p] = go[go[i][p - 1]][p - 1];
}
}
fr (i, 1, q) {
int s, e;
cin >> s >> e;
if (s == e) {
cout << "0\n";
continue;
}
if (a[s].se > a[e].se) {
cout << "impossible\n";
continue;
}
int v = s;
int ans = 0;
rf (p, 19, 0) {
if (!go[v][p]) continue;
int nxt = go[v][p];
if (a[nxt].se < a[e].se) {
v = go[v][p];
ans += pw(p);
}
}
while (1) {
if (a[to[v]].se == a[v].se || a[to[v]].se > a[e].se || a[v].se >= a[e].fi) {
break;
}
v = to[v];
ans++;
}
if (a[v].se >= a[e].fi) {
ans++;
cout << ans << "\n";
} else {
cout << "impossible\n";
}
}
return 0;
}
// fr (i, 1, n) {
// int p1 = lower_bound(all(u), a[i].fi) - u.begin();
// int p2 = upper_bound(all(u), a[i].se) - u.begin() - 1;
// if (max(0, p2 - p1 + 1) > 2) {
// assert(0);
// }
// }
// fr (i, 1, n) {
// int cnt = 0;
// fr (j, 1, n) {
// if (i == j) continue;
//
// if (a[j].fi <= a[i].se && a[i].se <= a[j].se) {
// cnt++;
// }
// }
// assert(cnt <= 1);
// }
fr (i, 1, q) {
int s, e;
cin >> s >> e;
if (s == e) {
ans[i] = 0;
continue;
}
if (a[s].se >= a[e].fi && a[s].se <= a[e].se) {
ans[i] = 1;
continue;
}
if (a[s].se > a[e].se) {
ans[i] = -1;
continue;
}
Q[e].pb({s, i});
}
sort(all(order), [](int i, int j) {
return a[i].se < a[j].se || (a[i].se == a[j].se && a[i].fi < a[j].fi);
});
fr (i, 1, n) {
to[i] = i;
d[i] = 0;
}
// subtask1 = 1;
if (q > 100 || n > 5000) {
subtask1 = 1;
}
ve<pii> add, del;
fr (idx, 0, sz(order) - 1) {
int i = order[idx];
int l = 0;
int r = idx - 1;
while (l < r) {
int mid = l + ((r - l) >> 1);
int j = order[mid];
if (a[j].se < a[i].fi) {
l = mid + 1;
} else {
r = mid;
}
}
if (a[order[l]].se < a[i].fi) {
l++;
}
if (l <= idx - 1) {
if (subtask1) {
rf (ptr, idx - 1, l) {
int j = order[ptr];
to[j] = i;
d[j] = 1;
}
} else {
add.pb({l, idx});
del.pb({idx, idx});
}
}
// rf (ptr, idx - 1, 0) {
// int j = order[ptr];
// if (a[j].se < a[i].fi) {
// break;
// }
//
// subtask1 &= ptr == idx - 1;
// to[j] = i;
// d[j] = 1;
// }
if (!subtask1 && sz(Q[i])) {
sort(all(add));
sort(all(del));
//
int ptr1 = 0;
int ptr2 = 0;
set<int> s;
fr (cur, 0, idx) {
while (ptr1 < sz(add) && add[ptr1].fi <= cur) {
s.insert(add[ptr1].se);
ptr1++;
}
while (ptr2 < sz(del) && del[ptr2].fi <= cur) {
s.erase(del[ptr2].se);
ptr2++;
}
int i = order[cur];
if (sz(s)) {
d[i] = 1;
// assert(to[i] == order[*s.rbegin()]);
to[i] = order[*s.rbegin()];
}
}
add.clear();
del.clear();
}
fe (cur, Q[i]) {
if (subtask1) {
auto p = get(cur.fi);
if (p.fi == i) {
ans[cur.se] = p.se;
} else {
ans[cur.se] = -1;
}
} else {
int v = cur.fi;
int sum = 0;
while (to[v] != v) {
sum += d[v];
v = to[v];
}
if (v == i) {
ans[cur.se] = sum;
} else {
ans[cur.se] = -1;
}
}
}
}
fr (i, 1, q) {
if (ans[i] == -1) {
cout << "impossible\n";
} else {
cout << ans[i] << "\n";
}
}
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
2644 KB |
Output is correct |
2 |
Correct |
88 ms |
13604 KB |
Output is correct |
3 |
Correct |
89 ms |
13596 KB |
Output is correct |
4 |
Correct |
126 ms |
13708 KB |
Output is correct |
5 |
Correct |
75 ms |
10440 KB |
Output is correct |
6 |
Correct |
72 ms |
10016 KB |
Output is correct |
7 |
Correct |
74 ms |
10048 KB |
Output is correct |
8 |
Correct |
61 ms |
7612 KB |
Output is correct |
9 |
Correct |
71 ms |
14116 KB |
Output is correct |
10 |
Correct |
90 ms |
14016 KB |
Output is correct |
11 |
Correct |
82 ms |
7840 KB |
Output is correct |
12 |
Correct |
49 ms |
8208 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
2644 KB |
Output is correct |
2 |
Correct |
1 ms |
2644 KB |
Output is correct |
3 |
Correct |
2 ms |
2772 KB |
Output is correct |
4 |
Correct |
2 ms |
2772 KB |
Output is correct |
5 |
Correct |
2 ms |
2644 KB |
Output is correct |
6 |
Correct |
2 ms |
2644 KB |
Output is correct |
7 |
Correct |
2 ms |
2644 KB |
Output is correct |
8 |
Correct |
2 ms |
2772 KB |
Output is correct |
9 |
Correct |
2 ms |
2652 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
2644 KB |
Output is correct |
2 |
Correct |
1 ms |
2644 KB |
Output is correct |
3 |
Correct |
2 ms |
2772 KB |
Output is correct |
4 |
Correct |
2 ms |
2772 KB |
Output is correct |
5 |
Correct |
2 ms |
2644 KB |
Output is correct |
6 |
Correct |
2 ms |
2644 KB |
Output is correct |
7 |
Correct |
2 ms |
2644 KB |
Output is correct |
8 |
Correct |
2 ms |
2772 KB |
Output is correct |
9 |
Correct |
2 ms |
2652 KB |
Output is correct |
10 |
Correct |
1 ms |
2644 KB |
Output is correct |
11 |
Correct |
2 ms |
2644 KB |
Output is correct |
12 |
Correct |
2 ms |
2772 KB |
Output is correct |
13 |
Correct |
2 ms |
2772 KB |
Output is correct |
14 |
Correct |
2 ms |
2644 KB |
Output is correct |
15 |
Correct |
2 ms |
2644 KB |
Output is correct |
16 |
Correct |
3 ms |
2644 KB |
Output is correct |
17 |
Correct |
2 ms |
2772 KB |
Output is correct |
18 |
Correct |
2 ms |
2644 KB |
Output is correct |
19 |
Incorrect |
43 ms |
4860 KB |
Output isn't correct |
20 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
2644 KB |
Output is correct |
2 |
Correct |
1 ms |
2644 KB |
Output is correct |
3 |
Correct |
2 ms |
2772 KB |
Output is correct |
4 |
Correct |
2 ms |
2772 KB |
Output is correct |
5 |
Correct |
2 ms |
2644 KB |
Output is correct |
6 |
Correct |
2 ms |
2644 KB |
Output is correct |
7 |
Correct |
2 ms |
2644 KB |
Output is correct |
8 |
Correct |
2 ms |
2772 KB |
Output is correct |
9 |
Correct |
2 ms |
2652 KB |
Output is correct |
10 |
Correct |
1 ms |
2644 KB |
Output is correct |
11 |
Correct |
1 ms |
2644 KB |
Output is correct |
12 |
Correct |
2 ms |
2772 KB |
Output is correct |
13 |
Correct |
2 ms |
2772 KB |
Output is correct |
14 |
Correct |
2 ms |
2644 KB |
Output is correct |
15 |
Correct |
2 ms |
2644 KB |
Output is correct |
16 |
Correct |
3 ms |
2644 KB |
Output is correct |
17 |
Correct |
2 ms |
2772 KB |
Output is correct |
18 |
Correct |
2 ms |
2644 KB |
Output is correct |
19 |
Correct |
56 ms |
13040 KB |
Output is correct |
20 |
Correct |
50 ms |
5440 KB |
Output is correct |
21 |
Execution timed out |
1577 ms |
5248 KB |
Time limit exceeded |
22 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
86 ms |
13632 KB |
Output is correct |
2 |
Correct |
93 ms |
13596 KB |
Output is correct |
3 |
Correct |
104 ms |
13608 KB |
Output is correct |
4 |
Correct |
72 ms |
14140 KB |
Output is correct |
5 |
Correct |
98 ms |
13948 KB |
Output is correct |
6 |
Correct |
106 ms |
13812 KB |
Output is correct |
7 |
Correct |
91 ms |
13756 KB |
Output is correct |
8 |
Correct |
77 ms |
13924 KB |
Output is correct |
9 |
Correct |
47 ms |
12964 KB |
Output is correct |
10 |
Correct |
99 ms |
13368 KB |
Output is correct |
11 |
Correct |
74 ms |
13176 KB |
Output is correct |
12 |
Correct |
84 ms |
13552 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
2644 KB |
Output is correct |
2 |
Correct |
88 ms |
13604 KB |
Output is correct |
3 |
Correct |
89 ms |
13596 KB |
Output is correct |
4 |
Correct |
126 ms |
13708 KB |
Output is correct |
5 |
Correct |
75 ms |
10440 KB |
Output is correct |
6 |
Correct |
72 ms |
10016 KB |
Output is correct |
7 |
Correct |
74 ms |
10048 KB |
Output is correct |
8 |
Correct |
61 ms |
7612 KB |
Output is correct |
9 |
Correct |
71 ms |
14116 KB |
Output is correct |
10 |
Correct |
90 ms |
14016 KB |
Output is correct |
11 |
Correct |
82 ms |
7840 KB |
Output is correct |
12 |
Correct |
49 ms |
8208 KB |
Output is correct |
13 |
Correct |
1 ms |
2644 KB |
Output is correct |
14 |
Correct |
1 ms |
2644 KB |
Output is correct |
15 |
Correct |
2 ms |
2772 KB |
Output is correct |
16 |
Correct |
2 ms |
2772 KB |
Output is correct |
17 |
Correct |
2 ms |
2644 KB |
Output is correct |
18 |
Correct |
2 ms |
2644 KB |
Output is correct |
19 |
Correct |
2 ms |
2644 KB |
Output is correct |
20 |
Correct |
2 ms |
2772 KB |
Output is correct |
21 |
Correct |
2 ms |
2652 KB |
Output is correct |
22 |
Correct |
1 ms |
2644 KB |
Output is correct |
23 |
Correct |
2 ms |
2644 KB |
Output is correct |
24 |
Correct |
2 ms |
2772 KB |
Output is correct |
25 |
Correct |
2 ms |
2772 KB |
Output is correct |
26 |
Correct |
2 ms |
2644 KB |
Output is correct |
27 |
Correct |
2 ms |
2644 KB |
Output is correct |
28 |
Correct |
3 ms |
2644 KB |
Output is correct |
29 |
Correct |
2 ms |
2772 KB |
Output is correct |
30 |
Correct |
2 ms |
2644 KB |
Output is correct |
31 |
Incorrect |
43 ms |
4860 KB |
Output isn't correct |
32 |
Halted |
0 ms |
0 KB |
- |