Submission #245361

#	Time	Username	Problem	Language	Result	Execution time	Memory
245361		lyc	Calvinball championship (CEOI15_teams)	C++14	100 / 100	396 ms	736 KiB

teams

#include <bits/stdc++.h>
using namespace std;

#define TRACE(x) cerr << #x << " :: " << x << endl
#define _ << " " <<
#define SZ(x) (int)(x).size()
#define ALL(x) (x).begin(),(x).end()
#define FOR(i,a,b) for(int i=(a);i<=(b);++i)
#define RFOR(i,a,b) for (int i=(a);i>=(b);--i)

const int mxN = 1e4+5;
const int mod = 1e6+7;

int N, A[mxN];
int dp[2][mxN][2];

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

    cin >> N;
    FOR(i,1,N){
        cin >> A[i];
    }

    FOR(j,0,N) FOR(x,0,1) dp[(N+1)&1][j][x] = 1;
    RFOR(i,N,1){
        int c = i&1, p = !c;
        FOR(j,0,i-1){
            dp[c][j][0] = 1LL * dp[p][j][0] * j % mod;
            dp[c][j][0] += dp[p][j+1][0];
            dp[c][j][0] %= mod;
            if (j < A[i]) {
                dp[c][j][1] = 1LL * dp[p][j][0] * j % mod;
                dp[c][j][1] += dp[p][j+1][(j+1 == A[i])];
                dp[c][j][1] %= mod;
            } else {
                dp[c][j][1] = 1LL * dp[p][j][0] * (A[i]-1) % mod;
                dp[c][j][1] += dp[p][j][1];
                dp[c][j][1] %= mod;
            }
            //TRACE(i _ j _ "|" _ dp[c][j][0] _ dp[c][j][1]);
        }
    }
    cout << dp[1][0][1] << '\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