Submission #647492

#	Time	Username	Problem	Language	Result	Execution time	Memory
647492		ymm	Calvinball championship (CEOI15_teams)	C++17	100 / 100	370 ms	724 KiB

teams

#include <bits/stdc++.h>
#define Loop(x,l,r) for (ll x = (l); x < (ll)(r); ++x)
#define LoopR(x,l,r) for (ll x = (r)-1; x >= (ll)(l); --x)
typedef long long ll;
typedef std::pair<int, int> pii;
typedef std::pair<ll , ll > pll;
using namespace std;

const int N = 10'010;
const int mod = 1e6+7;
ll dp[2][N];
ll dp_lte[2][N];
int a[N];
int n;

void update_dp(int i)
{
	int i2 = i&1;
	Loop (mx_st,0,N-1) {
		dp[i2][mx_st] = mx_st*dp[!i2][mx_st] + dp[!i2][mx_st+1];
		if (mx_st < a[i])
			dp_lte[i2][mx_st] = dp[i2][mx_st];
		else if (mx_st == a[i])
			dp_lte[i2][mx_st] = mx_st*dp[!i2][mx_st] + dp_lte[!i2][mx_st+1];
		else /* mx_st > a[i] */
			dp_lte[i2][mx_st] = a[i]*dp[!i2][mx_st] + dp_lte[!i2][mx_st];
		dp[i2][mx_st] %= mod;
		dp_lte[i2][mx_st] %= mod;
	}
}

int main()
{
	cin.tie(0) -> sync_with_stdio(false);
	cin >> n;
	Loop (i,0,n) {
		cin >> a[i];
		--a[i];
	}
	Loop (i,0,N)
		dp[n&1][i] = dp_lte[n&1][i] = 1;
	LoopR (i,0,n)
		update_dp(i);
	cout << dp_lte[0][0] << '\n';
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 10 / 10