360 2017 春招

#include <bits/stdc++.h>
using namespace std;
#define LL long long
const int mod = 1e9 + 7;
const int maxn = 1e5 + 10;
int N;
int num[maxn];
LL dp[maxn];

map<int, int> mp;

int main() {
    scanf("%d", &N);
    for(int i = 1; i <= N; i ++)
        scanf("%d", &num[i]);

    num[N + 1] = 10;
    memset(dp, 0, sizeof(dp));
    dp[1] = 1;
    for(int i = 2; i <= N+1; i ++) {
        mp.clear();
        for(int j = 1; i - j >= 1 && j <= 9; j ++) {
            if(mp[num[i - j]] == 0) {
                mp[num[i - j]] = 1;
                dp[i] += dp[i - j];
                dp[i] %= mod;
                continue;
            } else break;
        }
        dp[i] %= mod;
    }

    printf("%lld
", dp[N+1] % mod);
    return 0;
}