//Sylwia Sapkowska
#include <bits/stdc++.h>
#pragma GCC optimize("O3", "unroll-loops")
using namespace std;
void __print(int x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << "'" << x << "'";}
void __print(const char *x) {cerr << '"' << x << '"';}
void __print(const string &x) {cerr << '"' << x << '"';}
void __print(bool x) {cerr << (x ? "true" : "false");}
template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ", "; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? ", " : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#ifdef LOCAL
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
#define debug(x...)
#endif
#define int long long
typedef pair<int, int> T;
const int oo = 1e18, oo2 = 1e9+7, K = 30;
const int mod = 1e9+7;
int mul(int a, int b){
return (a*b)%mod;
}
void add(int &a, int b){
a += b;
if (a >= mod) a-=mod;
}
int add2(int a, int b){
a += b;
if (a >= mod) a-=mod;
return a;
}
void solve(){
int n; cin >> n;
vector<int>a(n+1), b(n+1);
vector<int>s = {0};
for (int i = 1; i<=n; i++) {
cin >> a[i] >> b[i];
s.emplace_back(a[i]);
s.emplace_back(b[i]);
s.emplace_back(a[i]+1);
s.emplace_back(b[i]-1);
}
sort(s.begin(), s.end());
s.erase(unique(s.begin(), s.end()), s.end());
debug(s);
vector<T>seg;
for (int i = 0; i<(int)s.size(); i++){
seg.emplace_back(s[i], s[i]);
if ((i+1) < (int)s.size() && s[i]+1 <= s[i+1]-1) seg.emplace_back(s[i]+1, s[i+1]-1);
}
debug(seg);
int m = (int)seg.size();
vector<int>dp(m, 0);
dp[0] = 1;
for (int i = 1; i<=n; i++){
auto new_dp = dp;
vector<int>pref(m);
pref[0] = dp[0];
for (int j = 1; j<m; j++) pref[j] = add2(pref[j-1], dp[j]);
debug(pref);
for (int j = 1; j<m; j++){
if (seg[j].first >= a[i] && seg[j].second <= b[i]){
add(new_dp[j], mul(pref[j-1], (seg[j].second-seg[j].first+1)));
}
}
dp.swap(new_dp);
debug(i, dp);
}
debug(dp);
int ans = 0;
for (auto x: dp) add(ans, x);
ans--;
if (ans < 0) ans += mod;
cout << ans << "\n";
}
int32_t main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int t = 1;
//cin >> t;
while (t--) solve();
return 0;
}
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
3 ms |
348 KB |
Output is correct |
| 2 |
Correct |
3 ms |
348 KB |
Output is correct |
| 3 |
Correct |
3 ms |
588 KB |
Output is correct |
| 4 |
Correct |
3 ms |
348 KB |
Output is correct |
| 5 |
Correct |
3 ms |
348 KB |
Output is correct |
| 6 |
Correct |
3 ms |
348 KB |
Output is correct |
| 7 |
Correct |
3 ms |
348 KB |
Output is correct |
| 8 |
Correct |
3 ms |
348 KB |
Output is correct |
| 9 |
Correct |
3 ms |
348 KB |
Output is correct |
| 10 |
Correct |
3 ms |
600 KB |
Output is correct |
| 11 |
Correct |
3 ms |
348 KB |
Output is correct |
| 12 |
Correct |
3 ms |
344 KB |
Output is correct |
| 13 |
Correct |
3 ms |
348 KB |
Output is correct |
| 14 |
Correct |
3 ms |
348 KB |
Output is correct |
| 15 |
Correct |
3 ms |
348 KB |
Output is correct |
| 16 |
Correct |
1 ms |
348 KB |
Output is correct |
| 17 |
Correct |
1 ms |
460 KB |
Output is correct |
| 18 |
Correct |
1 ms |
348 KB |
Output is correct |
| 19 |
Correct |
1 ms |
348 KB |
Output is correct |
| 20 |
Correct |
1 ms |
348 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
3 ms |
348 KB |
Output is correct |
| 2 |
Correct |
3 ms |
348 KB |
Output is correct |
| 3 |
Correct |
3 ms |
588 KB |
Output is correct |
| 4 |
Correct |
3 ms |
348 KB |
Output is correct |
| 5 |
Correct |
3 ms |
348 KB |
Output is correct |
| 6 |
Correct |
3 ms |
348 KB |
Output is correct |
| 7 |
Correct |
3 ms |
348 KB |
Output is correct |
| 8 |
Correct |
3 ms |
348 KB |
Output is correct |
| 9 |
Correct |
3 ms |
348 KB |
Output is correct |
| 10 |
Correct |
3 ms |
600 KB |
Output is correct |
| 11 |
Correct |
3 ms |
348 KB |
Output is correct |
| 12 |
Correct |
3 ms |
344 KB |
Output is correct |
| 13 |
Correct |
3 ms |
348 KB |
Output is correct |
| 14 |
Correct |
3 ms |
348 KB |
Output is correct |
| 15 |
Correct |
3 ms |
348 KB |
Output is correct |
| 16 |
Correct |
1 ms |
348 KB |
Output is correct |
| 17 |
Correct |
1 ms |
460 KB |
Output is correct |
| 18 |
Correct |
1 ms |
348 KB |
Output is correct |
| 19 |
Correct |
1 ms |
348 KB |
Output is correct |
| 20 |
Correct |
1 ms |
348 KB |
Output is correct |
| 21 |
Incorrect |
4 ms |
604 KB |
Output isn't correct |
| 22 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
1 ms |
348 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
3 ms |
348 KB |
Output is correct |
| 2 |
Correct |
3 ms |
348 KB |
Output is correct |
| 3 |
Correct |
3 ms |
588 KB |
Output is correct |
| 4 |
Correct |
3 ms |
348 KB |
Output is correct |
| 5 |
Correct |
3 ms |
348 KB |
Output is correct |
| 6 |
Correct |
3 ms |
348 KB |
Output is correct |
| 7 |
Correct |
3 ms |
348 KB |
Output is correct |
| 8 |
Correct |
3 ms |
348 KB |
Output is correct |
| 9 |
Correct |
3 ms |
348 KB |
Output is correct |
| 10 |
Correct |
3 ms |
600 KB |
Output is correct |
| 11 |
Correct |
3 ms |
348 KB |
Output is correct |
| 12 |
Correct |
3 ms |
344 KB |
Output is correct |
| 13 |
Correct |
3 ms |
348 KB |
Output is correct |
| 14 |
Correct |
3 ms |
348 KB |
Output is correct |
| 15 |
Correct |
3 ms |
348 KB |
Output is correct |
| 16 |
Correct |
1 ms |
348 KB |
Output is correct |
| 17 |
Correct |
1 ms |
460 KB |
Output is correct |
| 18 |
Correct |
1 ms |
348 KB |
Output is correct |
| 19 |
Correct |
1 ms |
348 KB |
Output is correct |
| 20 |
Correct |
1 ms |
348 KB |
Output is correct |
| 21 |
Incorrect |
4 ms |
604 KB |
Output isn't correct |
| 22 |
Halted |
0 ms |
0 KB |
- |
