HDUoj-------（1128）Self Numbers

Self Numbers

Time Limit: 20000/10000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 6227    Accepted Submission(s): 2728

Problem Description

In
1949 the Indian mathematician D.R. Kaprekar discovered a class of
numbers called self-numbers. For any positive integer n, define d(n) to
be n plus the sum of the digits of n. (The d stands for digitadition, a
term coined by Kaprekar.) For example, d(75) = 75 + 7 + 5 = 87. Given
any positive integer n as a starting point, you can construct the
infinite increasing sequence of integers n, d(n), d(d(n)), d(d(d(n))),
.... For example, if you start with 33, the next number is 33 + 3 + 3 =
39, the next is 39 + 3 + 9 = 51, the next is 51 + 5 + 1 = 57, and so you
generate the sequence
33, 39, 51, 57, 69, 84, 96, 111, 114, 120, 123, 129, 141, ...

The
number n is called a generator of d(n). In the sequence above, 33 is a
generator of 39, 39 is a generator of 51, 51 is a generator of 57, and
so on. Some numbers have more than one generator: for example, 101 has
two generators, 91 and 100. A number with no generators is a
self-number. There are thirteen self-numbers less than 100: 1, 3, 5, 7,
9, 20, 31, 42, 53, 64, 75, 86, and 97.

Write a program to output all positive self-numbers less than or equal 1000000 in increasing order, one per line.

 

Sample Output

1

3

5

7

9

20

31

42

53

64

|

|

<-- a lot more numbers

|

9903

9914

9925

9927

9938
9949
9960
9971
9982
9993
|
|
|

 

Source

Mid-Central USA 1998

尼玛，太简单了，之间就水过去了.....

代码：

 #include<cstdio>
 #include<cstring>
 #define maxn 1000001
 /*求个位数之和*/
 int work(int n)
 {
     int sum=;
     while(n>){
       sum+=n%;
       n/=;
     }
     return sum;
 }
 bool ans[maxn];
 int main(){
     int pos;
     //freopen("test.out","w",stdout);
     memset(ans,,sizeof(ans));
     for(int i=;i<maxn;i++){
         pos=i+work(i);
         if(pos<=&&!ans[pos]) ans[pos]=;
     }
     for(int i=;i<maxn;i++){
         if(!ans[i])printf("%d\n",i);
     }
 return ;
 }