hdu Children’s Queue
http://acm.hdu.edu.cn/game/entry/problem/show.php?chapterid=3§ionid=1&problemid=10
1 #include <cstdio> 2 #include <cstring> 3 #include <algorithm> 4 #define maxn 300000 5 using namespace std; 6 7 int n; 8 int a[1001][500]; 9 10 void inti() 11 { 12 a[1][0]=1; 13 a[2][0]=2; 14 a[3][0]=4; 15 a[4][0]=7; 16 for(int i=5; i<=1000; i++) 17 { 18 int c=0; 19 for(int j=0; j<=300; j++) 20 { 21 a[i][j]=a[i-1][j]+a[i-2][j]+a[i-4][j]+c; 22 c=a[i][j]/10; 23 a[i][j]%=10; 24 } 25 } 26 } 27 28 int main() 29 { 30 inti(); 31 while(scanf("%d",&n)!=EOF) 32 { 33 int i=4a99; 34 while(i>=0&&!a[n][i]) i--; 35 while(i>=0) 36 { 37 printf("%d",a[n][i]); 38 i--; 39 } 40 printf("\n"); 41 } 42 return 0; 43 }