#include <bits/stdc++.h>
using namespace std;
#define boost ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0)
#define fi first
#define se second
#define debug(x) cerr << " - " << #x << ": " << x << endl;
#define debugs(x, y) cerr << " - " << #x << ": " << x << " " << #y << ": " << y << endl;
#define debugii(x) cerr << " - " << #x << ": " << x.fi<<","<<x.se << endl;
#define sep() cerr << "--------------------" << endl;
#define all(x) (x).begin(),(x).end()
#define sz(x) (ll)x.size()
#define ll long long
#define int ll
#define ii pair<int,int>
#define v vector<int>
#define vii vector<ii>
#define vv vector<vector<int> >
#define mp make_pair
#define INF 1000000000
#define pb push_back
#define EPS 1e-9
const int MOD = 1000000007; // 998244353
int B[501],A[501];
v vec;
int n;
int dp[501][1005];
int solve(int i,int last){
if(i==n)
return 1;
//debugs(i,vec[last])
if(dp[i][last]!=-1)
return dp[i][last];
int ans=0;
if(B[i]>=last){
ans+=solve(i+1,last);
if(vec[last]<A[i])
ans=((ans%MOD)+(((B[i]-A[i]+1)*(solve(i+1,lower_bound(all(vec),B[i])-vec.begin())))%MOD))%MOD;
else
ans=((ans%MOD)+(((((B[i]-A[i])*(B[i]-A[i]+1))/2)*(solve(i+1,lower_bound(all(vec),B[i])-vec.begin())))%MOD))%MOD;
}
return dp[i][last]=ans%MOD;
}
main(){
boost;
memset(dp,-1,sizeof dp);
set<int> myset;
cin>>n;
for (int i = 0; i < n; ++i)
{
cin>>A[i]>>B[i];
myset.insert(A[i]);
myset.insert(B[i]);
}
vec.pb(0);
for(auto it:myset)
vec.pb(it);
cout<<solve(0,0);
return 0;
}
//long long
//array bounds
//special cases
//binary search
Compilation message
boat.cpp:43:7: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
main(){
^
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
14 ms |
4344 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
14 ms |
4344 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
5 ms |
4344 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
14 ms |
4344 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |