/*
Code written by Talant I.D.
*/
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair <int, int> pii;
typedef pair <ll, ll> pll;
#define precision(n) fixed << setprecision(n)
#define pb push_back
#define ub upper_bound
#define lb lower_bound
#define mp make_pair
#define eps (double)1e-9
#define PI 2*acos(0.0)
#define endl "\n"
#define sz(v) int((v).size())
#define all(v) v.begin(),v.end()
#define rall(v) v.rbegin(),v.rend()
#define do_not_disturb ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define OK cout << "OK" << endl;
const int mod = 998244353;
ll mode(ll a) {
a %= mod;
if (a < 0) a += mod;
return a;
}
ll subt(ll a, ll b) {
return mode(mode(a)-mode(b));
}
ll add(ll a, ll b) {
return mode(mode(a)+mode(b));
}
ll mult(ll a, ll b) {
return mode(mode(a)*mode(b));
}
ll binpow(ll a, ll b) {
ll res = 1;
while (b) {
if (b&1) res = mult(res, a);
a = mult(a, a);
b >>= 1;
}
return res;
}
ll divide(ll a, ll b) {
return mult(a, binpow(b, mod-2));
}
const int N = 1010;
int a[N], b[N], rng[N];
ll dp[N][N];
ll inv[N];
int n;
int main() {
do_not_disturb
vector <int> compressed;
inv[1] = 1;
cin >> n;
for (int i = 1; i <= n; i++) {
cin >> a[i] >> b[i];
b[i]++;
compressed.pb(a[i]);
compressed.pb(b[i]);
if (i > 1) inv[i] = binpow(i, mod-2);
}
sort(all(compressed));
compressed.resize(unique(all(compressed))-compressed.begin());
auto m = sz(compressed);
for (int j = 0; j < m-1; j++) {
rng[j+1] = compressed[j+1]-compressed[j];
}
for (int i = 1; i <= n; i++) {
a[i] = lb(all(compressed), a[i])-compressed.begin()+1;
b[i] = lb(all(compressed), b[i])-compressed.begin()+1;
}
for (int j = 0; j < m; j++) {
dp[0][j] = 1;
}
ll ans = 0;
for (int i = 1; i <= n; i++) {
for (int j = a[i]; j < b[i]; j++) {
ll res = rng[j];
ll x = rng[j], y = 1;
for (int k = i-1; k >= 0; k--) {
dp[i][j] = add(dp[i][j], res*dp[k][j-1]);
if (a[k] <= j && j < b[k]) {
x++; y++;
res = mult(mult(res, x), inv[y]);
}
}
}
for (int j = 1; j < m; j++) {
dp[i][j] = add(dp[i][j], dp[i][j-1]);
}
ans = add(ans, dp[i][m-1]);
}
cout << ans;
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
11 ms |
4300 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
11 ms |
4300 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
5 ms |
844 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
11 ms |
4300 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |