A Cubic number and A Cubic Number HDU

来源:互联网 发布:淘宝steam充值卡 编辑:程序博客网 时间:2024/05/29 06:53

A cubic number is the result of using a whole number in a multiplication three times. For example, 3×3×3=27so 27 is a cubic number. The first few cubic numbers are 1,8,27,64 and 125. Given an prime number pp. Check that if pp is a difference of two cubic numbers.
Input
The first of input contains an integer T (1≤T≤100) which is the total number of test cases.
For each test case, a line contains a prime number p(2p1012).
Output
For each test case, output ‘YES’ if given pp is a difference of two cubic numbers, or ‘NO’ if not.
Sample Input
10
2
3
5
7
11
13
17
19
23
29
Sample Output
NO
NO
NO
YES
NO
NO
NO
YES
NO
NO
问题是给定素数p,是否存在ab使得满足等式:

p=a3b3(a>b)
若存在输出YES,没有则NO
这个算数学题了吧,或是数论,这种题在acm已经是水题了。。。
易知:
p=(ab)(a2+ab+b2)

因为p为素数,所以ab=1,则:
p=(b+1)3b3=3b2+3b+1

转化为
3b2+3b+1p=0

是否有整数解的问题,这个就很显然了,只要验证9+12p1

代码就没必要写了