#include<bits/stdc++.h> using namespace std; using ll = long long; using vi = vector<int>; using pi = pair<int, int>; using vpi = vector<pi>; #define FOR(x, b, e) for(int x = b; x <= (e); ++x) #define FORD(x, b, e) for(int x = b; x >= (e); --x) #define REP(x, n) for(int x = 0; x < (n); ++x) #define ALL(c) (c).begin(), (c).end() #define ALLD(c) (c).rbegin(), (c).rend() #define SIZE(x) ((int)(x).size()) #define pb push_back #define pp emplace_back #define st first #define nd second #define sq(a) (a)*(a) const int inf = 1000000001; const int mod = 1000000007; const double eps = 1e-9; bool fleq(double a, double b){ return abs(a - b) < eps; } int n; ll dp[300100]; ll s[300100]; int main(){ ios_base::sync_with_stdio(0); cin.tie(0); cin >> n; FOR(i, 1, n){ cin >> s[i]; s[i] += s[i - 1]; } dp[0] = 1; FOR(i, 1, n){ FORD(j, i - 1, 0){ if(((s[i] - s[j])%mod)%2 == 0){ dp[i] = (dp[i] + dp[j]) % mod; } } } cout << dp[n] << '\n'; 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 | #include<bits/stdc++.h> using namespace std; using ll = long long; using vi = vector<int>; using pi = pair<int, int>; using vpi = vector<pi>; #define FOR(x, b, e) for(int x = b; x <= (e); ++x) #define FORD(x, b, e) for(int x = b; x >= (e); --x) #define REP(x, n) for(int x = 0; x < (n); ++x) #define ALL(c) (c).begin(), (c).end() #define ALLD(c) (c).rbegin(), (c).rend() #define SIZE(x) ((int)(x).size()) #define pb push_back #define pp emplace_back #define st first #define nd second #define sq(a) (a)*(a) const int inf = 1000000001; const int mod = 1000000007; const double eps = 1e-9; bool fleq(double a, double b){ return abs(a - b) < eps; } int n; ll dp[300100]; ll s[300100]; int main(){ ios_base::sync_with_stdio(0); cin.tie(0); cin >> n; FOR(i, 1, n){ cin >> s[i]; s[i] += s[i - 1]; } dp[0] = 1; FOR(i, 1, n){ FORD(j, i - 1, 0){ if(((s[i] - s[j])%mod)%2 == 0){ dp[i] = (dp[i] + dp[j]) % mod; } } } cout << dp[n] << '\n'; return 0; } |