简单题 没的说
滚动数组
1 #include <iostream> 2 #include <algorithm> 3 #include <queue> 4 #include <cstring> 5 #include <cstdio> 6 #include <vector> 7 #include <string> 8 #include <iterator> 9 #include <cmath> 10 #include <deque> 11 #include <stack> 12 #include <cctype> 13 using namespace std; 14 15 const int N = 2500; 16 const int INF = 0xfffffff; 17 18 typedef long long ll; 19 typedef long double ld; 20 21 #define INFL 0x7fffffffffffffffLL 22 #define met(a, b) memset(a, b, sizeof(a)) 23 #define rep(c, a, b) for (int c = a; c < b; c++) 24 #define nre(c, a, b) for (int c = a; c > b; c--) 25 26 //h(n) = ( (4*n-2) / (n+1) ) * h(n-1); 27 28 int ans[5][N]; 29 30 int main () 31 { 32 int n; 33 while (cin >> n) 34 { 35 met (ans, 0); 36 ans[1][0] = ans[2][0] = ans[3][0] = ans[4][0] = 1; 37 rep (i, 5, n+1) 38 { 39 int t = 0, m = i % 5; 40 rep (j, 0, N) 41 { 42 int x = ans[0][j] + ans[1][j] + ans[2][j] + ans[3][j] + ans[4][j] + t - ans[m][j]; 43 ans[m][j] = x % 10, t = x / 10; 44 } 45 } 46 int len = N - 1; 47 while (ans[n%5][len] == 0) len--; 48 while (len >= 0) cout << ans[n%5][len--]; 49 cout << endl; 50 } 51 return 0; 52 }
