Submission #4609072

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Source Code Expand

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

const int mod = 1e9 + 7;

int add(int &x, int y) {
  x += y;
  if (x >= mod) {
    x -= mod;
  }
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n;
  cin >> n;
  vector<int> a(n);
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    a[i]--;
  }
  a.erase(unique(a.begin(), a.end()), a.end());
  n = (int) a.size();
  vector<int> dp((int) 2e5, 0);
  dp[a[0]] = 1;
  for (int i = 1; i < n; i++) {
    add(dp[a[i]], dp[a[i - 1]]);
  }
  cout << dp[a[n - 1]] << '\n';
  return 0;
}

Submission Info

Judge Result