This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include<bits/stdc++.h>
#define ll long long
#define pb push_back
#define in insert
#define fi first
#define se second
#define vl vector<ll>
#define all(v) v.begin(), v.end()
#define endl "\n"
using namespace std;
const int sz = 1e3 + 5; /// mind this
const int MAX = 2e6 + 123;
const int BS = 61;
const int mod = 1e6 + 7;
ll dp[sz][sz];
ll bp(ll a, ll b){
ll res = 1;
a %= mod;
while(b){
if(b & 1){
res = (res * a) % mod;
}
a = (a * a) % mod;
b >>= 1;
}
return res;
}
void solve(){
ll n, i, j, hi = 0, ans = 0;
cin >> n;
vl v(n + 1), fp(n + 1, -1);
for(i = 1; i <= n; i++){
cin >> v[i];
hi = max(hi, v[i]);
if(fp[v[i]] == -1 ){
fp[v[i]] = i;
}
dp[i][1] = 1;
}
for(i = 1; i <= n; i ++){
for(j = 2; j <= hi; j++){
if(i < fp[j]){break;}
dp[i][j] = (dp[i - 1][j - 1] + (dp[i - 1][j] * j) % mod) % mod;
}
}
for(i = 1; i <= hi; i++){
ans = (ans + dp[n][i]) % mod;
}
cout << ans << endl;
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
ll t = 1;
// cin >> t;
while(t--){
solve();
}
}
/*
*/
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |