题目地址:
http://acm.hdu.edu.cn/showproblem.php?pid=1128
题目描述:
Self Numbers
Time Limit: 20000/10000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 5733 Accepted Submission(s): 2521
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.
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 | | |
题意:
计算不能 组成d(n)的 数字。
题解:
从1到1000000,把能组成d(n)的数字 标记出来,剩下的就是不能组成的数字了。
代码:
/*
we should set the array size beyond the standard more such as +50 or +500
*/
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<math.h>
#include<iostream>
#include<algorithm>
#define M 1000000
using namespace std;
int flag[1000000+500]={0};
int digit[7+5]={0};//the number of the bit
/*d(n)*/
int d1(int num)
{
int sum=num;
int bit=0;
while(num>0)
{
bit=num%10;
num/=10;
sum+=bit;
}
return(sum);
}
/*d(n)*/
int d(int num)
{
int sum=num;
int i=0;
for(i=0;i<=7-1;i++)
{
sum+=digit[i];
}
return(sum);//sum > 1000000 so will lead to the flag[d{i}] overflow
}
/*big data plus one*/
int PlusDigit()
{
int i=0;
digit[0]++;
for(i=0;i<=7-1;i++)
{
if(digit[i]>=10)
{
int c=digit[i]/10;
digit[i+1]+=c;
digit[i]=digit[i]%10;
}
}
return(0);
}
/*for test*/
int test()
{
return(0);
}
/*main process*/
int MainProc()
{
int i=0;
for(i=1,digit[0]=1;i<=M;i++)//907019
{
flag[d(i)]=1;
if(!flag[i])
{
printf("%d\n",i);
}
PlusDigit();
}
return(0);
}
int main()
{
MainProc();
return(0);
}