HDUOJ Children’s Queue

雨点打透心脏的1/2处 2022-03-31 02:59 183阅读 0赞

# Children’s Queue #

**Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)  
Total Submission(s): 8835 Accepted Submission(s): 2813**

Problem Description

There are many students in PHT School. One day, the headmaster whose name is PigHeader wanted all students stand in a line. He prescribed that girl can not be in single. In other words, either no girl in the queue or more than one girl stands side by side. The case n=4 (n is the number of children) is like  
FFFF, FFFM, MFFF, FFMM, MFFM, MMFF, MMMM  
Here F stands for a girl and M stands for a boy. The total number of queue satisfied the headmaster’s needs is 7. Can you make a program to find the total number of queue with n children?

Input

There are multiple cases in this problem and ended by the EOF. In each case, there is only one integer n means the number of children (1<=n<=1000)

Output

For each test case, there is only one integer means the number of queue satisfied the headmaster’s needs.

Sample Input

Sample Output

大数。。 公式 f（x）=f(x-1)+f(x-2)-F（x-4）;

代码：

![ContractedBlock.gif][] ![ExpandedBlockStart.gif][]

1 #include<iostream>
     2 #include<cstdio>
     3 #define maxn 250
     4 #define len 1000
     5 using namespace std;
     6 int a[len+1][maxn+1]={
           {
           1},{
           2},{
           4},{
           7}};
     7 int main()
     8 {
     9     int i,j,n,s,c=0;
    10     for(i=4;i<=len;i++)
    11     {
    12         for(c=j=0;j<=maxn;j++)
    13         {
    14           s=a[i-1][j]+a[i-2][j]+a[i-4][j]+c;
    15           a[i][j]=s%10;
    16           c=(s-a[i][j])/10;
    17         }
    18     }
    19     while(cin>>n)
    20     {
    21      for(i=maxn;a[n-1][i]==0;i--);
    22      for(j=i;j>=0;j--)
    23      {
    24          printf("%d",a[n-1][j]);
    25      }
    26      printf("\n");
    27     }
    28     return 0;
    29 }

[ContractedBlock.gif]: https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif
[ExpandedBlockStart.gif]: /images/20220331/be3e1146d579415fb862905ff721c540.png