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ID | 题目 | 提交者 | 结果 | 用时 | 内存 | 语言 | 文件大小 | 提交时间 | 测评时间 |
---|---|---|---|---|---|---|---|---|---|
#729043 | #9566. Topology | ucup-team045# | RE | 8ms | 199596kb | C++20 | 4.4kb | 2024-11-09 16:25:01 | 2024-11-09 16:25:07 |
Judging History
answer
#include<iostream>
#include<cstring>
#include<vector>
#include<stdint.h>
using namespace std;
using LL = long long;
template<const int T>
struct ModInt {
const static int mod = T;
int x;
ModInt(int x = 0) : x(x % mod) {}
ModInt(long long x) : x(int(x % mod)) {}
int val() { return x; }
ModInt operator + (const ModInt &a) const { int x0 = x + a.x; return ModInt(x0 < mod ? x0 : x0 - mod); }
ModInt operator - (const ModInt &a) const { int x0 = x - a.x; return ModInt(x0 < 0 ? x0 + mod : x0); }
ModInt operator * (const ModInt &a) const { return ModInt(1LL * x * a.x % mod); }
ModInt operator / (const ModInt &a) const { return *this * a.inv(); }
bool operator == (const ModInt &a) const { return x == a.x; };
bool operator != (const ModInt &a) const { return x != a.x; };
void operator += (const ModInt &a) { x += a.x; if (x >= mod) x -= mod; }
void operator -= (const ModInt &a) { x -= a.x; if (x < 0) x += mod; }
void operator *= (const ModInt &a) { x = 1LL * x * a.x % mod; }
void operator /= (const ModInt &a) { *this = *this / a; }
friend ModInt operator + (int y, const ModInt &a){ int x0 = y + a.x; return ModInt(x0 < mod ? x0 : x0 - mod); }
friend ModInt operator - (int y, const ModInt &a){ int x0 = y - a.x; return ModInt(x0 < 0 ? x0 + mod : x0); }
friend ModInt operator * (int y, const ModInt &a){ return ModInt(1LL * y * a.x % mod);}
friend ModInt operator / (int y, const ModInt &a){ return ModInt(y) / a;}
friend ostream &operator<<(ostream &os, const ModInt &a) { return os << a.x;}
friend istream &operator>>(istream &is, ModInt &t){return is >> t.x;}
ModInt pow(int64_t n) const {
ModInt res(1), mul(x);
while(n){
if (n & 1) res *= mul;
mul *= mul;
n >>= 1;
}
return res;
}
ModInt inv() const {
int a = x, b = mod, u = 1, v = 0;
while (b) {
int t = a / b;
a -= t * b; swap(a, b);
u -= t * v; swap(u, v);
}
if (u < 0) u += mod;
return u;
}
};
using mint = ModInt<998244353>;
const int maxn = 5005;
vector<int> g[maxn];
int sz[maxn], dep[maxn];
mint f[maxn], mul[maxn], fact[maxn];
int n;
void dfs1(int u){
mul[u] = 1;
sz[u] = 1;
for(auto j : g[u]){
dfs1(j);
sz[u] += sz[j];
mul[u] *= mul[j];
}
mul[u] *= sz[u];
f[u] = fact[sz[u]] / mul[u];
}
// dp[u][i] : u正好在排第i的方案数(不包括u当前子树内点)
mint dp[maxn][maxn], C[maxn][maxn];
mint ans[maxn];
mint get(int x, int y){
if (y == 0){
return (x == 0 ? 1 : 0);
}
return C[x + y - 1][y - 1];
}
void dfs2(int u){
// cout << u << ":\n";
// for(int i = 1; i <= n; i++) cout << dp[u][i] << " \n"[i == n];
const int s = g[u].size();
vector<mint> pre(s), suf(s);
for(int i = 0; i < s; i++){
pre[i] = suf[i] = f[g[u][i]];
}
for(int i = 1; i < s; i++) pre[i] *= pre[i - 1];
for(int i = s - 2; i >= 0; i--) suf[i] *= suf[i + 1];
for(int x = 0; x < s; x++){
int j = g[u][x];
mint t = (x - 1 >= 0 ? pre[x - 1] : 1) * (x + 1 < s ? suf[x + 1] : 1);
mint sum = 0;
for(int i = 1; i <= n; i++){
dp[j][i] = sum;
// [i, n - sz[u] + 1]
sum += dp[u][i] * t * get(sz[u] - sz[j] - 1, n - sz[u] + 1 - i + 1);
}
// 当前点数是 n - sz[j] + 1(包括j本身)
// 后面的点只能在i后面
// [j, n - sz[j] + 1]
ans[j] = dp[j][j] * f[j] * get(sz[j] - 1, n - sz[j] + 1 - j + 1);
dfs2(j);
}
}
int main(){
#ifdef LOCAL
freopen("data.in", "r", stdin);
freopen("data.out", "w", stdout);
#endif
cin.tie(0);
cout.tie(0);
ios::sync_with_stdio(0);
cin >> n;
for(int i = 2; i <= n; i++){
int x;
cin >> x;
g[x].push_back(i);
}
for(int i = 0; i <= n; i++){
for(int j = 0; j <= i; j++){
if (!j) C[i][j] = 1;
else C[i][j] = C[i - 1][j - 1] + C[i - 1][j];
}
}
fact[0] = 1;
for(int i = 1; i <= n; i++) fact[i] = fact[i - 1] * i;
dep[1] = 1;
dfs1(1);
ans[1] = f[1];
dp[1][1] = 1;
dfs2(1);
for(int i = 1; i <= n; i++){
cout << ans[i] << " \n"[i == n];
}
}
詳細信息
Test #1:
score: 100
Accepted
time: 8ms
memory: 199596kb
input:
4 1 1 2
output:
3 2 1 2
result:
ok 4 number(s): "3 2 1 2"
Test #2:
score: -100
Runtime Error
input:
9 1 1 2 2 3 3 4 5