結果
問題 | No.907 Continuous Kadomatu |
ユーザー |
|
提出日時 | 2019-04-23 12:56:27 |
言語 | C++14 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 612 ms / 2,000 ms |
コード長 | 2,592 bytes |
コンパイル時間 | 828 ms |
コンパイル使用メモリ | 80,576 KB |
実行使用メモリ | 215,936 KB |
最終ジャッジ日時 | 2024-10-13 12:55:24 |
合計ジャッジ時間 | 11,598 ms |
ジャッジサーバーID (参考情報) |
judge3 / judge2 |
(要ログイン)
ファイルパターン | 結果 |
---|---|
sample | AC * 5 |
other | AC * 25 |
ソースコード
#include <iostream>#include <vector>#include <algorithm>using namespace std;const int MAX_N = 300;const int MOD = 1e9 + 7;struct mint {int n;mint(int n_ = 0) : n(n_) {}};mint operator+(mint a, mint b) { a.n += b.n; if (a.n >= MOD) a.n -= MOD; return a; }mint operator-(mint a, mint b) { a.n -= b.n; if (a.n < 0) a.n += MOD; return a; }mint operator*(mint a, mint b) { return (long long)a.n * b.n % MOD; }mint &operator+=(mint &a, mint b) { return a = a + b; }mint &operator-=(mint &a, mint b) { return a = a - b; }mint &operator*=(mint &a, mint b) { return a = a * b; }mint dp[MAX_N+1][MAX_N*2][MAX_N+1];mint I[1000];mint modpow(mint a, int b) {mint res = 1;while (b > 0) {if (b & 1) res *= a;a *= a;b >>= 1;}return res;}mint modinv(mint a) {return modpow(a, MOD - 2);}mint f(mint *a, mint l, mint r) {mint res = 0;mint L = 1;mint R = 1;for (int i = 0; i <= MAX_N; i++) {L *= l;R *= r;res += a[i] * (R - L) * I[i + 1];}return res;}int main() {I[1] = 1;for (int i = 2; i < 1000; i++) {I[i] = I[MOD % i] * (MOD - MOD / i);}int N;cin >> N;vector<int> A(N), B(N), C;for (int i = 0; i < N; i++) {cin >> A[i] >> B[i];C.push_back(A[i]);C.push_back(B[i]);}sort(C.begin(), C.end());C.erase(unique(C.begin(), C.end()), C.end());int M = C.size() - 1;{int l = lower_bound(C.begin(), C.end(), A[0]) - C.begin();int r = lower_bound(C.begin(), C.end(), B[0]) - C.begin();for (int i = l; i < r; i++) {dp[0][i][0] = modinv(B[0] - A[0]);}}for (int i = 1; i < N; i++) {int l = lower_bound(C.begin(), C.end(), A[i]) - C.begin();int r = lower_bound(C.begin(), C.end(), B[i]) - C.begin();mint s = 0;for (int j = 0; j < M; j++) {dp[i][j][0] += s;dp[i][j][0] -= f(dp[i - 1][j], 0, C[j]);for (int k = 0; k < MAX_N; k++) {dp[i][j][k + 1] += dp[i - 1][j][k] * I[k + 1];}s += f(dp[i - 1][j], C[j], C[j + 1]);}if (i % 2 == 0) {for (int j = 0; j < M; j++) {for (int k = 0; k <= MAX_N; k++) {dp[i][j][k] *= MOD - 1;}dp[i][j][0] += s;}}mint v = modinv(B[i] - A[i]);for (int j = 0; j < M; j++) {for (int k = 0; k <= MAX_N; k++) {if (l <= j && j < r) {dp[i][j][k] *= v;} else {dp[i][j][k] = 0;}}}}mint ans = 0;for (int i = 0; i < M; i++) {ans += f(dp[N - 1][i], C[i], C[i + 1]);}cout << ans.n << '\n';}