# hdu1128 Self Numbers--哈希表水题

2016-12-02 12:52:28来源:网络收集作者:Mark人点击

/2014th7cj/d/file/p/20161129/mu0k5hdpb3j.php 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 sequence33, 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
|
|
|

#include
#include
#include
using namespace std;
int hash1[1000005];
int Func(int i)
{
int x = 0;
while (i)
{
x += (i % 10);
i = i / 10;
}
return x;
}
int main()
{
memset(hash1, 1, sizeof(hash1));
for (int i = 1; i <= 1000000; i++)
{
int num = i;
num += Func(i);
hash1[num] = 0;
}
for (int i = 1; i <= 1000000; i++)
{
if (hash1[i])
printf("%d/n", i);
}
return 0;
}