hdu 1028Ignatius and the Princess III

http://acm.hdu.edu.cn/showproblem.php?pid=1028

and the Princess IIITime Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 7214    Accepted Submission(s): 5118


Problem Description
"Well, it seems the first problem is too easy. I will let you know how foolish you are later." feng5166 says.

"The second problem is, given an positive integer N, we define an equation like this:
  N=a[1]+a[2]+a[3]+...+a[m];
  a[i]>0,1<=m<=N;
My question is how many different equations you can find for a given N.
For example, assume N is 4, we can find:
  4 = 4;
  4 = 3 + 1;
  4 = 2 + 2;
  4 = 2 + 1 + 1;
  4 = 1 + 1 + 1 + 1;
so the result is 5 when N is 4. Note that "4 = 3 + 1" and "4 = 1 + 3" is the same in this problem. Now, you do it!"
 
Input
The input contains several test cases. Each test case contains a positive integer N(1<=N<=120) which is mentioned above. The input is terminated by the end of file.
 
Output
For each test case, you have to output a line contains an integer P which indicate the different equations you have found.
 
Sample Input
4 10 20
 
Sample Output
5 42 627
 模板题:
View Code
 1 #include<stdio.h>
 2 int main()
 3 {
 4     int n,i,j,k;
 5     int sum[122];//sum[i]存储的是可以组合成i的所有总数 
 6     int temp[122];// 存储的是每一次的情况 
 7     while(~scanf("%d",&n))
 8     {
 9         
10         
11         for(i=0;i<=n;i++)
12         {
13             sum[i]=1;//初始化第一表达式,由数值1可以组合成0-n,这是一种组合方法。 
14             temp[i]=0;
15         }
16         for(i=2;i<=n;i++)//i表示第i个表达式 
17         {
18             
19             for(j=0;j<=n;j++)
20             {
21                 for(k=0;j+k<=n;k+=i)
22                 {
23                     temp[j+k]+=sum[j];
24                     /*
25                     这句话是最不好理解的
26                     1.temp[j+k]每次加是叠加不同结果。
27                     2.加上sum[j]其实是第一个表达式系数乘以第二表达式系数(此处为1) 
28                     j+k是形成数的大小,也是函数里面的指数,指数相加,系数相乘。 
29                     不懂,,请无视,同不懂 
30                     
31                     */ 
32                 }
33             }
34             for(j=0;j<=n;j++)
35             {
36                 sum[j]=temp[j];
37                 temp[j]=0;
38             }
39         }
40         printf("%d\n",sum[n]);
41     }
42 }
原文地址:https://www.cnblogs.com/1114250779boke/p/2630147.html