結果
問題 | No.916 Encounter On A Tree |
ユーザー |
|
提出日時 | 2019-10-25 22:13:13 |
言語 | C++14 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 54 ms / 2,000 ms |
コード長 | 2,232 bytes |
コンパイル時間 | 1,742 ms |
コンパイル使用メモリ | 172,600 KB |
実行使用メモリ | 27,964 KB |
最終ジャッジ日時 | 2024-09-13 04:07:39 |
合計ジャッジ時間 | 5,121 ms |
ジャッジサーバーID (参考情報) |
judge2 / judge4 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 5 |
other | AC * 56 |
ソースコード
#include <bits/stdc++.h>using namespace std;const int64_t MOD = 1e9+7;void add(int64_t& a, int64_t b){a = (a+b) % MOD;}void mul(int64_t& a, int64_t b){a = a*b % MOD;}vector<int64_t> fact, seq_inv, fact_inv;void create_fact_mod(int num){fact[0] = fact[1] = 1;for(int i=2; i<=num; i++) fact[i] = fact[i-1] * i % MOD;}void create_seq_inv_mod(int num){seq_inv[0] = seq_inv[1] = 1;for(int i=2; i<=num; i++) seq_inv[i] = (MOD - MOD/i) * seq_inv[MOD%i] % MOD;}void create_fact_inv_mod(int num){fact_inv[0] = fact_inv[1] = 1;for(int i=2; i<=num; i++) fact_inv[i] = fact_inv[i-1] * seq_inv[i] % MOD;}void create_mod_tables(int num){fact.resize(num+1);seq_inv.resize(num+1);fact_inv.resize(num+1);create_fact_mod(num);create_seq_inv_mod(num);create_fact_inv_mod(num);}int64_t comb_mod(int n, int k){return fact[n] * fact_inv[n-k] % MOD * fact_inv[k] % MOD;}int64_t perm_mod(int n, int k){return fact[n] * fact_inv[n-k] % MOD;}int64_t power_mod(int64_t num, int64_t power){int64_t prod = 1;num %= MOD;while(power > 0){if(power&1) prod = prod * num % MOD;num = num * num % MOD;power >>= 1;}return prod;}int64_t extgcd(int64_t a, int64_t b, int64_t& x, int64_t& y){int64_t d = a;if(b != 0){d = extgcd(b, a%b, y, x);y -= (a/b) * x;}else{x = 1; y = 0;}return d;}int64_t inv_mod(int64_t a){int64_t x, y;extgcd(a, MOD, x, y);return (MOD + x%MOD) % MOD;}void fail(){cout << 0 << endl;exit(0);}int main(){int D, L, R, K;cin >> D >> L >> R >> K;int ld = 1, rd = 1;while((1<<ld) <= L) ld++;while((1<<rd) <= R) rd++;int rest = K - (rd-ld);if(rest%2) fail();if(rest < 0) fail();int lca = ld - rest/2;if(lca <= 0) fail();int64_t ans = 1<<(lca-1);mul(ans, 2);if(lca < ld) mul(ans, 1<<(ld-lca-1));mul(ans, 1<<(rd-lca-1));create_mod_tables(1<<20);for(int d=1; d<=D; d++){int num = 1<<(d-1);if(d==ld) num--;if(d==rd) num--;mul(ans, fact[num]);}cout << ans << endl;return 0;}