#include <bits/stdc++.h> using namespace std; int main() { ios::sync_with_stdio(0); cin.tie(0); constexpr int p = 1e9 + 7; int n; cin >> n; vector<int> dp(n+1), pref(n+1); for (int i = 1; i <= n; ++i) { cin >> pref[i]; pref[i] = (pref[i] + pref[i-1]) % p; } dp[0] = 1; for (int i = 1; i <= n; ++i) { for (int j = i-1; j >= 0; --j) { bool pred = not (((pref[i] - pref[j] + p) % p) % 2); dp[i] = (dp[i] + dp[j]*pred) % p; } } cout << dp[n]; }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 | #include <bits/stdc++.h> using namespace std; int main() { ios::sync_with_stdio(0); cin.tie(0); constexpr int p = 1e9 + 7; int n; cin >> n; vector<int> dp(n+1), pref(n+1); for (int i = 1; i <= n; ++i) { cin >> pref[i]; pref[i] = (pref[i] + pref[i-1]) % p; } dp[0] = 1; for (int i = 1; i <= n; ++i) { for (int j = i-1; j >= 0; --j) { bool pred = not (((pref[i] - pref[j] + p) % p) % 2); dp[i] = (dp[i] + dp[j]*pred) % p; } } cout << dp[n]; } |