67 lines
1.5 KiB
C++
67 lines
1.5 KiB
C++
#include <bits/stdc++.h>
|
|
using namespace std;
|
|
const int MOD = 998244353;
|
|
|
|
#ifdef DEBUG
|
|
#define PRINT_VALUE(v){cout<<#v<<" :"<<v<<endl;}
|
|
#define PRINT_ARRAY(arr,size){cout<<#arr<<" [";for(int i=1;i<=size;i++){cout<<arr[i]<<(i!=size?",":"]\n");}}
|
|
#define DEBUG_PRINT(c){cout<<c<<endl;}
|
|
#endif
|
|
|
|
#ifndef DEBUG
|
|
#define PRINT_VALUE(v)
|
|
#define PRINT_ARRAY(arr,size)
|
|
#define DEBUG_PRINT(c)
|
|
#endif
|
|
|
|
int main() {
|
|
int n, m;
|
|
cin >> n >> m;
|
|
vector<int> lim(n);
|
|
for (int i = 0; i < n; ++i) {
|
|
cin >> lim[i];
|
|
}
|
|
|
|
vector<vector<int>> dp(n + 1, vector<int>(m + 1, 0));
|
|
dp[0][0] = 1;
|
|
|
|
vector<int> positions;
|
|
for (int i = 1; i <= n; ++i) {
|
|
if (lim[i - 1] == 0) {
|
|
positions.push_back(i);
|
|
}
|
|
}
|
|
|
|
int total_permutations = 1;
|
|
for (int i = 1; i <= positions.size(); ++i) {
|
|
total_permutations = (total_permutations * i) % MOD;
|
|
}
|
|
|
|
for (int i = 1; i <= n; ++i) {
|
|
if (lim[i - 1] != 0) {
|
|
for (int j = 0; j <= m; ++j) {
|
|
dp[i][j] = dp[i - 1][j];
|
|
}
|
|
} else {
|
|
for (int j = 0; j <= m; ++j) {
|
|
for (int k = 0; k < i; ++k) {
|
|
if (j - k >= 0) {
|
|
dp[i][j] = (dp[i][j] + dp[i - 1][j - k]) % MOD;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
int result = 0;
|
|
for (int j = 0; j <= m; ++j) {
|
|
result = (result + dp[n][j]) % MOD;
|
|
}
|
|
|
|
result = (result * total_permutations) % MOD;
|
|
|
|
cout << result << endl;
|
|
|
|
return 0;
|
|
}
|