Problem Statement
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You enjoy working with numbers that contain only square digits (namely, 0, 1, 4 and 9). The sequence containing only these digits is 0, 1, 4, 9, 10, 11, 14... Return the
n-th term (indexed from 0) in this sequence. |
Definition
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| Class: |
SquareDigitNumbers |
| Method: |
getNumber |
| Parameters: |
int |
| Returns: |
int |
| Method signature: |
int getNumber(int n) |
| (be sure your method is public) |
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Limits
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| Time limit (s): |
2.000 |
| Memory limit (MB): |
64 |
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Constraints
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n will be between 0 and 1000, inclusive. |
Examples
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| 0) |
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Returns: 0
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| The first square digit number is 0. |
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| 1) |
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| 2) |
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| 3) |
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| 4) |
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解题思路：
第一次在ＴＣ上切题，还是经过菠萝爷的指导才慢慢开始做的，总的来说，ｄｉｖ２的２５０分的题都是简单题，只要认真推敲下，就能切出来．．
这题的意思是说，有一些数，这些数字都是由０ １ ４ ９组成的，那么输入一个ｎ，让你输出这个数，注意下标是从０开始的．然后呢，将只含有０ １ ４ ９的数字从
i = 0 -＞i = 100000变化，只要求出了满足这个条件的第一个数字，就把他按顺序放进ａ数组中，注意，也是要从０开始放，一直到最后一个数字判断结束，然后直接根据输入的ｎ的值返回我们需要的结果就ＯＫ了．
代码：
# include<cstdio>
# include<iostream>
using namespace std;
# define MAX 100000
int a[MAX];
class SquareDigitNumbers
{
public:
int getNumber( int n )
{
int flag;
int i;
int j = 0;
for ( i = 0;i <= 100000;i++ )
{
int x = i;
flag = 1;
while ( x != 0 )
{
if ( x%10 == 0 ||x%10 == 1||x%10 == 4||x%10 == 9 )
{
x /= 10;
continue;
}
flag = 0;
break;
}
if ( flag )
{
a[j++] = i;
}
}
return a[n];
}
};