# include <stdio.h>
# include <bits/stdc++.h>
#define _USE_MATH_DEFINES_
#define ll long long
#define ld long double
#define Accepted 0
#define pb push_back
#define mp make_pair
#define sz(x) (int)(x.size())
#define every(x) x.begin(),x.end()
#define F first
#define S second
#define For(i,x,y) for (int i = x; i <= y; i ++)
#define FOr(i,x,y) for (int i = x; i >= y; i --)
#define SpeedForce ios_base::sync_with_stdio(0), cin.tie(0)
// ROAD to... Red
using namespace std;
inline bool isvowel (char c) {
c = tolower(c);
if (c == 'a' || c == 'e' || c == 'i' || c == 'y' || c == 'o' || c == 'u') return 1;
return 0;
}
const double eps = 0.000001;
const ld pi = acos(-1);
const int maxn = 1e7 + 9;
const int mod = 1000007;
const ll MOD = 1e18 + 9;
const ll INF = 1e18 + 123;
const int inf = 2e9 + 11;
const int mxn = 1e6 + 9;
const int N = 6e5 + 123;
const int M = 22;
const int pri = 997;
const int Magic = 2101;
const int dx[] = {-1, 0, 1, 0};
const int dy[] = {0, -1, 0, 1};
int n;
int dp[5][10005];
int a[10005];
int p[10005];
int main () {
SpeedForce;
cin >> n;
int ans = 1;
For (i, 1, n) {
cin >> a[i];
p[i] = max(p[i - 1], a[i]);
}
int t = *max_element(a + 1, a + n + 1);
For (i, 0, n + 1) dp[0][i] = 1;
For (i, 1, n) {
for (int j = n + 1; j >= 0; j --) {
dp[i][j] = (j * (ll)dp[i - 1][j]) % mod + dp[i - 1][j + 1];
if (dp[i][j] >= mod) dp[i][j] -= mod;
}
}
/*
For (i, 0, n - 1) {
cout << i << ":\n";
for (int j = n; j >= 1; j --) {
cout << j << ' ' << dp[i][j] << '\n';
}
} */
int mx = 0;
for (int i = n - 1; i >= 0; i --) {
ans += (a[i + 1] - 1) * (ll)dp[(n - i - 1) & 1][p[i]];
for (int j = i; j >= 0; j --) {
dp[i & 1][j] = (j * (ll)dp[(i + 1) & 1][j]) % mod + dp[(i + 1) & 1][j + 1];
if (dp[i & 1][j] >= mod) dp[i & 1][j] -= mod;
}
}
cout << ans << '\n';
return Accepted;
}
// Coded By OB
Compilation message
teams.cpp: In function 'int main()':
teams.cpp:57:8: warning: unused variable 't' [-Wunused-variable]
int t = *max_element(a + 1, a + n + 1);
^
teams.cpp:73:6: warning: unused variable 'mx' [-Wunused-variable]
int mx = 0;
^~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
376 KB |
Output is correct |
2 |
Correct |
2 ms |
512 KB |
Output is correct |
3 |
Correct |
2 ms |
512 KB |
Output is correct |
4 |
Correct |
2 ms |
512 KB |
Output is correct |
5 |
Correct |
2 ms |
512 KB |
Output is correct |
6 |
Correct |
2 ms |
512 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
3 ms |
752 KB |
Execution killed with signal 11 (could be triggered by violating memory limits) |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
3 ms |
752 KB |
Execution killed with signal 11 (could be triggered by violating memory limits) |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
3 ms |
808 KB |
Execution killed with signal 11 (could be triggered by violating memory limits) |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
3 ms |
916 KB |
Execution killed with signal 11 (could be triggered by violating memory limits) |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
3 ms |
916 KB |
Execution killed with signal 11 (could be triggered by violating memory limits) |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
3 ms |
928 KB |
Execution killed with signal 11 (could be triggered by violating memory limits) |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
4 ms |
1420 KB |
Execution killed with signal 11 (could be triggered by violating memory limits) |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
4 ms |
1464 KB |
Execution killed with signal 11 (could be triggered by violating memory limits) |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
4 ms |
1572 KB |
Execution killed with signal 11 (could be triggered by violating memory limits) |
2 |
Halted |
0 ms |
0 KB |
- |