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>
using namespace std;
#define ll long long
#define ld long long
#define mod 1000007
int main(){
int n;
cin>>n;
vector<ll> v(n + 1, 0), pr(n + 1, 0);
for (int i = 1; i <= n; i++){
cin>>v[i];
pr[i] = max(pr[i - 1], v[i]);
}
vector<vector<ll>> dp(2, vector<ll>(n + 1, 0));
for (int i = 0; i <= n; i++){
dp[1][i] = 1;
}
ll ans = 0, la = 0;
for (int i = n; i >= 1; i--){
for (int j = 1; j <= i; j++){
dp[0][j] = dp[1][j] * j;
dp[0][j] += dp[1][j + 1];
dp[0][j] %= mod;
}
ll su = v[i] - 1;
la = pr[i - 1];
for (int j = 1; j <= su; j++){
ans += dp[1][max(la, (ll)j)];
ans %= mod;
}
ans %= mod;
la = max(v[i], la);
swap(dp[0], dp[1]);
dp[0].assign(n + 1, 0);
}
cout<<(ans + 1) % mod<<"\n";
}
# | 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... |