#include <bits/stdc++.h>
#define fr(i, n, m) for(int i = (n); i < (m); i ++)
#define pb push_back
#define st first
#define nd second
#define pq priority_queue
#define all(x) begin(x), end(x)
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pii;
const int i_inf = 1e9;
const ll inf = 1e10;
const ll mod = 1e9+7;
const ld eps = 1e-13;
const ld pi = 3.14159265359;
mt19937 _rand(time(NULL));
clock_t z;
const int mxn = 505;
ll modpow(ll x, ll n){
if(n == 0) return 1%mod;
ll u = modpow(x, n/2);
u = (u * u) % mod;
if(n % 2) u = (u * x) % mod;
return u;
}
ll inverse(ll x){
return modpow(x, mod-2);
}
ll fakt[mxn];
ll ifakt[mxn];
ll BC[mxn][mxn];
ll bc1(ll n, ll k){
if(n < k) return 0;
return (fakt[n]*((ifakt[k]*ifakt[n-k]) % mod)) % mod;
}
ll precomp[mxn];
void pre(ll n){
ll tot = 1;
precomp[0] = 1;
fr(i, 0, mxn-1){
tot *= (n-i);
tot %= mod;
precomp[i+1] = tot;
}
}
ll bc2(ll n, ll k){
if(n < k) return 0;
return (precomp[k]*ifakt[k])%mod;
}
ll store[mxn];
void pre2(ll a_len){
fr(LEN, 2, mxn){
store[LEN] = 0;
fr(len, 2, LEN+1){
ll ways = (bc2(a_len, len)*BC[LEN-2][len-2])%mod;
store[LEN] += ways;
store[LEN] %= mod;
}
}
}
int n;
ll l[mxn], r[mxn];
ll DP1[mxn];
ll DP2[mxn];
void solve(){
fakt[0] = 1;
fr(i, 1, mxn){
fakt[i] = (fakt[i-1]*i)%mod;
}
fr(i, 0, mxn){
ifakt[i] = inverse(fakt[i]);
}
fr(i, 0, mxn){
fr(j, 0, mxn){
BC[i][j] = bc1(i, j);
}
}
cin >> n;
fr(i, 0, n){
cin >> l[i] >> r[i];
}
vector<pair<ll, int> > v;
fr(i, 0, n){
v.pb({l[i], -i});
v.pb({r[i],i+1});
}
sort(all(v));
vector<int> active;
DP1[0] = 1;
ll prv = 0;
ll a_len;
for(auto u : v){
int id = u.nd;
if(id > 0){
a_len = u.st - prv;
}
else{
a_len = u.st - prv-1;
}
fr(i, 0, mxn) DP2[i] = DP1[i];
pre(a_len);
pre2(a_len);
fr(i, 0, (int)active.size()){
ll sum = 0;
fr(k, 0, active[i]+1){
sum += DP1[k];
sum %= mod;
}
fr(j, i, (int)active.size()){
if(i == j){
ll ways = a_len % mod;
DP2[active[j]+1] += (ways*sum)%mod;
DP2[active[j]+1] %= mod;
}
else{
DP2[active[j]+1] += (store[j-i+1] * sum) % mod;
}
}
}
fr(i, 0, mxn){
DP1[i] = DP2[i];
}
if(id <= 0){
prv = u.st-1;
active.pb(-id);
sort(all(active));
}else{
prv = u.st;
active.erase(find(all(active), id-1));
sort(all(active));
}
}
ll ans = 0;
fr(i, 1, n+1){
ans += DP1[i];
ans %= mod;
}
cout<<ans<<endl;
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
solve();
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
742 ms |
2356 KB |
Output is correct |
2 |
Correct |
726 ms |
2380 KB |
Output is correct |
3 |
Correct |
726 ms |
2360 KB |
Output is correct |
4 |
Correct |
731 ms |
2252 KB |
Output is correct |
5 |
Correct |
754 ms |
2372 KB |
Output is correct |
6 |
Correct |
725 ms |
2360 KB |
Output is correct |
7 |
Correct |
729 ms |
2380 KB |
Output is correct |
8 |
Correct |
735 ms |
2360 KB |
Output is correct |
9 |
Correct |
759 ms |
2380 KB |
Output is correct |
10 |
Correct |
729 ms |
2252 KB |
Output is correct |
11 |
Correct |
740 ms |
2380 KB |
Output is correct |
12 |
Correct |
737 ms |
2380 KB |
Output is correct |
13 |
Correct |
731 ms |
2380 KB |
Output is correct |
14 |
Correct |
748 ms |
2376 KB |
Output is correct |
15 |
Correct |
727 ms |
2380 KB |
Output is correct |
16 |
Correct |
642 ms |
2380 KB |
Output is correct |
17 |
Correct |
624 ms |
2380 KB |
Output is correct |
18 |
Correct |
627 ms |
2372 KB |
Output is correct |
19 |
Correct |
644 ms |
2380 KB |
Output is correct |
20 |
Correct |
622 ms |
2380 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
742 ms |
2356 KB |
Output is correct |
2 |
Correct |
726 ms |
2380 KB |
Output is correct |
3 |
Correct |
726 ms |
2360 KB |
Output is correct |
4 |
Correct |
731 ms |
2252 KB |
Output is correct |
5 |
Correct |
754 ms |
2372 KB |
Output is correct |
6 |
Correct |
725 ms |
2360 KB |
Output is correct |
7 |
Correct |
729 ms |
2380 KB |
Output is correct |
8 |
Correct |
735 ms |
2360 KB |
Output is correct |
9 |
Correct |
759 ms |
2380 KB |
Output is correct |
10 |
Correct |
729 ms |
2252 KB |
Output is correct |
11 |
Correct |
740 ms |
2380 KB |
Output is correct |
12 |
Correct |
737 ms |
2380 KB |
Output is correct |
13 |
Correct |
731 ms |
2380 KB |
Output is correct |
14 |
Correct |
748 ms |
2376 KB |
Output is correct |
15 |
Correct |
727 ms |
2380 KB |
Output is correct |
16 |
Correct |
642 ms |
2380 KB |
Output is correct |
17 |
Correct |
624 ms |
2380 KB |
Output is correct |
18 |
Correct |
627 ms |
2372 KB |
Output is correct |
19 |
Correct |
644 ms |
2380 KB |
Output is correct |
20 |
Correct |
622 ms |
2380 KB |
Output is correct |
21 |
Correct |
888 ms |
2380 KB |
Output is correct |
22 |
Correct |
958 ms |
2380 KB |
Output is correct |
23 |
Correct |
874 ms |
2380 KB |
Output is correct |
24 |
Correct |
936 ms |
2364 KB |
Output is correct |
25 |
Correct |
924 ms |
2380 KB |
Output is correct |
26 |
Correct |
1044 ms |
2380 KB |
Output is correct |
27 |
Correct |
1066 ms |
2384 KB |
Output is correct |
28 |
Correct |
1079 ms |
2380 KB |
Output is correct |
29 |
Correct |
1080 ms |
2364 KB |
Output is correct |
30 |
Correct |
750 ms |
2380 KB |
Output is correct |
31 |
Correct |
738 ms |
2380 KB |
Output is correct |
32 |
Correct |
750 ms |
2380 KB |
Output is correct |
33 |
Correct |
752 ms |
2372 KB |
Output is correct |
34 |
Correct |
735 ms |
2380 KB |
Output is correct |
35 |
Correct |
769 ms |
2372 KB |
Output is correct |
36 |
Correct |
740 ms |
2380 KB |
Output is correct |
37 |
Correct |
770 ms |
2380 KB |
Output is correct |
38 |
Correct |
760 ms |
2380 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
179 ms |
2308 KB |
Output is correct |
2 |
Correct |
183 ms |
2336 KB |
Output is correct |
3 |
Correct |
179 ms |
2372 KB |
Output is correct |
4 |
Correct |
189 ms |
2252 KB |
Output is correct |
5 |
Correct |
374 ms |
2332 KB |
Output is correct |
6 |
Correct |
183 ms |
2332 KB |
Output is correct |
7 |
Correct |
185 ms |
2252 KB |
Output is correct |
8 |
Correct |
201 ms |
2336 KB |
Output is correct |
9 |
Correct |
196 ms |
2336 KB |
Output is correct |
10 |
Correct |
195 ms |
2340 KB |
Output is correct |
11 |
Correct |
177 ms |
2252 KB |
Output is correct |
12 |
Correct |
196 ms |
2332 KB |
Output is correct |
13 |
Correct |
198 ms |
2336 KB |
Output is correct |
14 |
Correct |
175 ms |
2252 KB |
Output is correct |
15 |
Correct |
177 ms |
2336 KB |
Output is correct |
16 |
Correct |
147 ms |
2252 KB |
Output is correct |
17 |
Correct |
146 ms |
2252 KB |
Output is correct |
18 |
Correct |
149 ms |
2252 KB |
Output is correct |
19 |
Correct |
145 ms |
2252 KB |
Output is correct |
20 |
Correct |
155 ms |
2344 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
742 ms |
2356 KB |
Output is correct |
2 |
Correct |
726 ms |
2380 KB |
Output is correct |
3 |
Correct |
726 ms |
2360 KB |
Output is correct |
4 |
Correct |
731 ms |
2252 KB |
Output is correct |
5 |
Correct |
754 ms |
2372 KB |
Output is correct |
6 |
Correct |
725 ms |
2360 KB |
Output is correct |
7 |
Correct |
729 ms |
2380 KB |
Output is correct |
8 |
Correct |
735 ms |
2360 KB |
Output is correct |
9 |
Correct |
759 ms |
2380 KB |
Output is correct |
10 |
Correct |
729 ms |
2252 KB |
Output is correct |
11 |
Correct |
740 ms |
2380 KB |
Output is correct |
12 |
Correct |
737 ms |
2380 KB |
Output is correct |
13 |
Correct |
731 ms |
2380 KB |
Output is correct |
14 |
Correct |
748 ms |
2376 KB |
Output is correct |
15 |
Correct |
727 ms |
2380 KB |
Output is correct |
16 |
Correct |
642 ms |
2380 KB |
Output is correct |
17 |
Correct |
624 ms |
2380 KB |
Output is correct |
18 |
Correct |
627 ms |
2372 KB |
Output is correct |
19 |
Correct |
644 ms |
2380 KB |
Output is correct |
20 |
Correct |
622 ms |
2380 KB |
Output is correct |
21 |
Correct |
888 ms |
2380 KB |
Output is correct |
22 |
Correct |
958 ms |
2380 KB |
Output is correct |
23 |
Correct |
874 ms |
2380 KB |
Output is correct |
24 |
Correct |
936 ms |
2364 KB |
Output is correct |
25 |
Correct |
924 ms |
2380 KB |
Output is correct |
26 |
Correct |
1044 ms |
2380 KB |
Output is correct |
27 |
Correct |
1066 ms |
2384 KB |
Output is correct |
28 |
Correct |
1079 ms |
2380 KB |
Output is correct |
29 |
Correct |
1080 ms |
2364 KB |
Output is correct |
30 |
Correct |
750 ms |
2380 KB |
Output is correct |
31 |
Correct |
738 ms |
2380 KB |
Output is correct |
32 |
Correct |
750 ms |
2380 KB |
Output is correct |
33 |
Correct |
752 ms |
2372 KB |
Output is correct |
34 |
Correct |
735 ms |
2380 KB |
Output is correct |
35 |
Correct |
769 ms |
2372 KB |
Output is correct |
36 |
Correct |
740 ms |
2380 KB |
Output is correct |
37 |
Correct |
770 ms |
2380 KB |
Output is correct |
38 |
Correct |
760 ms |
2380 KB |
Output is correct |
39 |
Correct |
179 ms |
2308 KB |
Output is correct |
40 |
Correct |
183 ms |
2336 KB |
Output is correct |
41 |
Correct |
179 ms |
2372 KB |
Output is correct |
42 |
Correct |
189 ms |
2252 KB |
Output is correct |
43 |
Correct |
374 ms |
2332 KB |
Output is correct |
44 |
Correct |
183 ms |
2332 KB |
Output is correct |
45 |
Correct |
185 ms |
2252 KB |
Output is correct |
46 |
Correct |
201 ms |
2336 KB |
Output is correct |
47 |
Correct |
196 ms |
2336 KB |
Output is correct |
48 |
Correct |
195 ms |
2340 KB |
Output is correct |
49 |
Correct |
177 ms |
2252 KB |
Output is correct |
50 |
Correct |
196 ms |
2332 KB |
Output is correct |
51 |
Correct |
198 ms |
2336 KB |
Output is correct |
52 |
Correct |
175 ms |
2252 KB |
Output is correct |
53 |
Correct |
177 ms |
2336 KB |
Output is correct |
54 |
Correct |
147 ms |
2252 KB |
Output is correct |
55 |
Correct |
146 ms |
2252 KB |
Output is correct |
56 |
Correct |
149 ms |
2252 KB |
Output is correct |
57 |
Correct |
145 ms |
2252 KB |
Output is correct |
58 |
Correct |
155 ms |
2344 KB |
Output is correct |
59 |
Correct |
1119 ms |
2380 KB |
Output is correct |
60 |
Correct |
1133 ms |
2380 KB |
Output is correct |
61 |
Correct |
1113 ms |
2380 KB |
Output is correct |
62 |
Correct |
1126 ms |
2380 KB |
Output is correct |
63 |
Correct |
1159 ms |
2380 KB |
Output is correct |
64 |
Correct |
1329 ms |
2380 KB |
Output is correct |
65 |
Correct |
1315 ms |
2380 KB |
Output is correct |
66 |
Correct |
1319 ms |
2380 KB |
Output is correct |
67 |
Correct |
1315 ms |
2504 KB |
Output is correct |
68 |
Correct |
1315 ms |
2380 KB |
Output is correct |
69 |
Correct |
1098 ms |
2380 KB |
Output is correct |
70 |
Correct |
1079 ms |
2380 KB |
Output is correct |
71 |
Correct |
1089 ms |
2380 KB |
Output is correct |
72 |
Correct |
1091 ms |
2372 KB |
Output is correct |
73 |
Correct |
1086 ms |
2380 KB |
Output is correct |
74 |
Correct |
888 ms |
2380 KB |
Output is correct |
75 |
Correct |
868 ms |
2376 KB |
Output is correct |
76 |
Correct |
887 ms |
2384 KB |
Output is correct |
77 |
Correct |
864 ms |
2500 KB |
Output is correct |
78 |
Correct |
883 ms |
2380 KB |
Output is correct |