Find a function from N to N, such that for all elements, there is
infinite elements mapped to it.
Open ended problem (function)
2013-10-10 2:04 am
回答 (2)
2013-10-19 3:49 am
✔ 最佳答案
suggested solution:圖片參考：http://imgcld.yimg.com/8/n/HA08446686/o/20131018194734.jpg
2013-10-19 09:51:17 補充：
To CRebecca:
f(84)=f(1x2^6+0x2^5+1x2^4+0x2^3+1x2^2+0x2^1+0x2^0)=1+1+1+0=3
Your function is simpler and easier to understand.
2013-10-19 9:55 am
An easy answer: f(n)= (sum of digits of n)
for example f(56)=5+6=11, f(128)=1+2+8=11
x=(10^n -1)/9 = 1111..11, then f(x)=n, f(10x)=n, f(100x)=n, ...
2013-10-19 01:56:07 補充：
To: yc
As your fn. f(∑a(i)2^i) = ∑a(2i)2^(2i), a(i)=0 or 1, then f(?)=3
for example f(56)=5+6=11, f(128)=1+2+8=11
x=(10^n -1)/9 = 1111..11, then f(x)=n, f(10x)=n, f(100x)=n, ...
2013-10-19 01:56:07 補充：
To: yc
As your fn. f(∑a(i)2^i) = ∑a(2i)2^(2i), a(i)=0 or 1, then f(?)=3
收錄日期: 2021-04-13 19:45:08
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