#include <bits/stdc++.h> #define ll long long #define str string #define pii pair<int, int> #define pll pair<ll, ll> #define fi first #define se second #define vc vector<char> #define vvc vector<vc> #define vi vector<int> #define vvi vector<vi> #define vvvi vector<vvi> #define vvvvi vector<vvvi> #define vll vector<ll> #define vvll vector<vll> #define vvvll vector<vvll> #define vvvvll vector<vvvll> #define vs vector<str> #define vvs vector<vs> #define vpii vector<pii> #define vvpii vector<vpii> #define vpll vector<pll> #define vvpll vector<vpll> #define vb vector<bool> #define vvb vector<vb> #define rep(i, a, b) for (int i = (a); i < int(b); i++) #define repi(i, a, b) for (int i = (a); i <= int(b); i++) using namespace std; #define ui unsigned int void solve() { ll n; cin >> n; vll A(n); ll sum = 0; ll MOD = 1000000000 + 7; rep(i, 0, n) { cin >> A[i]; sum += (ll)A[i]; } if (sum < MOD) { ll sumdp[2] = {1, 0}; vll dp(n + 1, 0); dp[0] = 1; rep(i, 0, n) { if (A[i] % 2 == 1) { swap(sumdp[0], sumdp[1]); } dp[i + 1] = sumdp[0]; sumdp[0] = (sumdp[0] + dp[i + 1]) % MOD; } cout << dp[n] << '\n'; } else { vll dp(n + 1, 0); dp[0] = 1; for (int i = 0; i < n; i++) { ll sm = 0; for (int j = i; j >= 0; j--) { sm += A[j]; if ((sm % MOD) % 2 == 0) { dp[i + 1] = (dp[i + 1] + dp[j]) % MOD; } } } cout << dp[n] << '\n'; } } int main() { ios::sync_with_stdio(false); cin.tie(nullptr); bool _multipleTestCases = false; if (_multipleTestCases) { ll t; cin >> t; while (t--) solve(); } else { solve(); } return 0; }
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 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 | #include <bits/stdc++.h> #define ll long long #define str string #define pii pair<int, int> #define pll pair<ll, ll> #define fi first #define se second #define vc vector<char> #define vvc vector<vc> #define vi vector<int> #define vvi vector<vi> #define vvvi vector<vvi> #define vvvvi vector<vvvi> #define vll vector<ll> #define vvll vector<vll> #define vvvll vector<vvll> #define vvvvll vector<vvvll> #define vs vector<str> #define vvs vector<vs> #define vpii vector<pii> #define vvpii vector<vpii> #define vpll vector<pll> #define vvpll vector<vpll> #define vb vector<bool> #define vvb vector<vb> #define rep(i, a, b) for (int i = (a); i < int(b); i++) #define repi(i, a, b) for (int i = (a); i <= int(b); i++) using namespace std; #define ui unsigned int void solve() { ll n; cin >> n; vll A(n); ll sum = 0; ll MOD = 1000000000 + 7; rep(i, 0, n) { cin >> A[i]; sum += (ll)A[i]; } if (sum < MOD) { ll sumdp[2] = {1, 0}; vll dp(n + 1, 0); dp[0] = 1; rep(i, 0, n) { if (A[i] % 2 == 1) { swap(sumdp[0], sumdp[1]); } dp[i + 1] = sumdp[0]; sumdp[0] = (sumdp[0] + dp[i + 1]) % MOD; } cout << dp[n] << '\n'; } else { vll dp(n + 1, 0); dp[0] = 1; for (int i = 0; i < n; i++) { ll sm = 0; for (int j = i; j >= 0; j--) { sm += A[j]; if ((sm % MOD) % 2 == 0) { dp[i + 1] = (dp[i + 1] + dp[j]) % MOD; } } } cout << dp[n] << '\n'; } } int main() { ios::sync_with_stdio(false); cin.tie(nullptr); bool _multipleTestCases = false; if (_multipleTestCases) { ll t; cin >> t; while (t--) solve(); } else { solve(); } return 0; } |