最近碰到的笔试题# Java - 爪哇娇娃
w*n
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1.
A binary gap within a positive integer N is any maximal sequence of
consecutive zeros that is surrounded by ones at both ends in the binary
representation of N.
For example, number 9 has binary representation 1001 and contains a binary
gap of length 2. The number 529 has binary representation 1000010001) and
contains two binary gaps: one of length 4 and one of length 3. The number 20
has binary representation 10100 and contains one binary gap of length 1.
The number 15 has binary representation 1111 and has no binary gaps.
Write a function:
class Solution { public int solution(int N); }
that, given a positive integer N, returns the length of its longest binary
gap. The function should return 0 if N doesn't contain a binary gap.
For example, given N = 1041 the function should return 5, because N has
binary representation10000010001 and so its longest binary gap is of length
5.
Assume that:
N is an integer within the range [1..2,147,483,647].
Complexity:
expected worst-case time complexity is O(log(N));
expected worst-case space complexity is O(1).
2.
Function D is defined for a given integer N as follows:
D(N) = N when 0 ≤ N ≤ 9;
D(N) = the product of the digits in the decimal representation of abs(N)
otherwise.
Sequence S is constructed as follows:
S[0] = N
S[1] = D(N)
S[2] = D(D(N))
...
S[K] = DK(N)
...
For example, consider N = 6942. D(N) = 6*9*4*2 = 432. Initial values of the
sequence S constructed for N are: 6942, 432, 24, 8, 8, ... From the first
instance of 8, the sequence becomes constant.
Write a function:
class Solution { public int solution(int N); }
that, given an integer N, returns the smallest non-negative integer K such
that S[K] = S[K+1], where S is the sequence constructed for integer N. The
function should return −1 if no such K exists.
For example, given N = 6942, the function should return 3, as explained
above.
Assume that:
N is an integer within the range [−2,000,000,000..2,000,000,000].
Complexity:
expected worst-case time complexity is O(log(N));
expected worst-case space complexity is O(1).
3.
Use multi-threading program to calculate the expression xy/(x+y), where the
variable x and y has to be input from screen. (You will get 0 credit if you
simply output x*y/(x+y) without using multi-threading programming).
4.
Input an arithmetic expression from screen, then parse the expression and
find the result. The expression only contains +, –, * and /. Here are some
examples.
Input: 2 – 3 * 1.5/0.5
Output: –7
Input: 1.5 + ab
Output: Illegal input.
A binary gap within a positive integer N is any maximal sequence of
consecutive zeros that is surrounded by ones at both ends in the binary
representation of N.
For example, number 9 has binary representation 1001 and contains a binary
gap of length 2. The number 529 has binary representation 1000010001) and
contains two binary gaps: one of length 4 and one of length 3. The number 20
has binary representation 10100 and contains one binary gap of length 1.
The number 15 has binary representation 1111 and has no binary gaps.
Write a function:
class Solution { public int solution(int N); }
that, given a positive integer N, returns the length of its longest binary
gap. The function should return 0 if N doesn't contain a binary gap.
For example, given N = 1041 the function should return 5, because N has
binary representation10000010001 and so its longest binary gap is of length
5.
Assume that:
N is an integer within the range [1..2,147,483,647].
Complexity:
expected worst-case time complexity is O(log(N));
expected worst-case space complexity is O(1).
2.
Function D is defined for a given integer N as follows:
D(N) = N when 0 ≤ N ≤ 9;
D(N) = the product of the digits in the decimal representation of abs(N)
otherwise.
Sequence S is constructed as follows:
S[0] = N
S[1] = D(N)
S[2] = D(D(N))
...
S[K] = DK(N)
...
For example, consider N = 6942. D(N) = 6*9*4*2 = 432. Initial values of the
sequence S constructed for N are: 6942, 432, 24, 8, 8, ... From the first
instance of 8, the sequence becomes constant.
Write a function:
class Solution { public int solution(int N); }
that, given an integer N, returns the smallest non-negative integer K such
that S[K] = S[K+1], where S is the sequence constructed for integer N. The
function should return −1 if no such K exists.
For example, given N = 6942, the function should return 3, as explained
above.
Assume that:
N is an integer within the range [−2,000,000,000..2,000,000,000].
Complexity:
expected worst-case time complexity is O(log(N));
expected worst-case space complexity is O(1).
3.
Use multi-threading program to calculate the expression xy/(x+y), where the
variable x and y has to be input from screen. (You will get 0 credit if you
simply output x*y/(x+y) without using multi-threading programming).
4.
Input an arithmetic expression from screen, then parse the expression and
find the result. The expression only contains +, –, * and /. Here are some
examples.
Input: 2 – 3 * 1.5/0.5
Output: –7
Input: 1.5 + ab
Output: Illegal input.
