제출 #580604

#제출 시각아이디문제언어결과실행 시간메모리
580604vovamr캥거루 (CEOI16_kangaroo)C++17
0 / 100
1 ms212 KiB
#include <bits/stdc++.h> #include <ext/pb_ds/assoc_container.hpp> #include <ext/pb_ds/tree_policy.hpp> #define fi first #define se second #define ll long long #define ld long double #define sz(x) ((int)(x).size()) #define all(x) (x).begin(), (x).end() #define pb push_back #define mpp make_pair #define ve vector using namespace std; using namespace __gnu_pbds; template<class T> using oset = tree<T,null_type,less<T>,rb_tree_tag,tree_order_statistics_node_update>; const ll inf = 1e18; const int iinf = 1e9; typedef pair<ll, ll> pll; typedef pair<int, int> pii; mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count()); template <typename T> inline bool chmin(T& a, T b) { return (a > b ? a = b, 1 : 0); } template <typename T> inline bool chmax(T& a, T b) { return (a < b ? a = b, 1 : 0); } const int md = 1e9 + 7; inline int add(int a, int b) { a += b; if (a >= md){a -= md;} return a; } inline int mul(int a, int b) { return (ll)a * b % md; } inline void solve() { int n, s, t; cin >> n >> s >> t; ve<ve<int>> dp(n + 5, ve<int> (n + 5)); dp[1][1] = 1; for (int i = 1; i < n; ++i) { for (int j = 1; j <= i; ++j) { if (i + 1 == s || i + 1 == t) { dp[i + 1][j] = add(dp[i + 1][j], dp[i][j]); dp[i + 1][j + 1] = add(dp[i + 1][j + 1], dp[i][j]); } else { int ways = j + 1 - (i + 1 > s) - (i + 1 > t); dp[i + 1][j + 1] = add(dp[i + 1][j + 1], mul(ways, dp[i][j])); dp[i + 1][j - 1] = add(dp[i + 1][j], mul(dp[i][j], j - 1)); } } } cout << dp[n][1]; } signed main() { ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0); int q = 1; // cin >> q; while (q--) solve(); cerr << fixed << setprecision(3) << "Time execution: " << (double)clock() / CLOCKS_PER_SEC << endl; }
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...