#include<cstdio> #include<iostream> #include<algorithm> #include<string> #include<vector> #include<unordered_map> using namespace std; typedef vector<int> VI; typedef long long LL; #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 VAR(v, n) __typeof(n) v = (n) #define ALL(c) (c).begin(), (c).end() #define SIZE(x) ((int)(x).size()) #define FOREACH(i, c) for(VAR(i, (c).begin()); i != (c).end(); ++i) #define PB push_back #define ST first #define ND second int p = 1e9 + 7; int main() { ios_base::sync_with_stdio(0); int n; cin >> n; VI a(n); REP(i, n) cin >> a[i]; VI dp(n + 1); dp[0] = 1; REP(i, n) { int j = i; int sum = 0; while(j >= 0) { sum = (sum + a[j]) % p; if(sum % 2 == 0) dp[i + 1] = (dp[i + 1] + dp[j]) % p; j--; } } 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 | #include<cstdio> #include<iostream> #include<algorithm> #include<string> #include<vector> #include<unordered_map> using namespace std; typedef vector<int> VI; typedef long long LL; #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 VAR(v, n) __typeof(n) v = (n) #define ALL(c) (c).begin(), (c).end() #define SIZE(x) ((int)(x).size()) #define FOREACH(i, c) for(VAR(i, (c).begin()); i != (c).end(); ++i) #define PB push_back #define ST first #define ND second int p = 1e9 + 7; int main() { ios_base::sync_with_stdio(0); int n; cin >> n; VI a(n); REP(i, n) cin >> a[i]; VI dp(n + 1); dp[0] = 1; REP(i, n) { int j = i; int sum = 0; while(j >= 0) { sum = (sum + a[j]) % p; if(sum % 2 == 0) dp[i + 1] = (dp[i + 1] + dp[j]) % p; j--; } } cout << dp[n] << '\n'; return 0; } |