标签：des java os io strong for ar art cti
Example 1: Write a function to reverse a string.
Example Java code:
public static String reverse ( String s ) {
int length = s.length(), last =
length - 1;
char[] chars = s.toCharArray();
for ( int i = 0; i < length/2;
i++ ) {
char c = chars[i];
chars[i] = chars[last - i];
chars[last - i] = c;
}
return new String(chars);
}
Example output for "Madam, I‘m Adam": madA m‘I ,madaM
Example 2: Write function to compute Nth fibonacci number:
Java and C/C++:
static long fib(int n) {
return n <= 1 ? n : fib(n-1) +
fib(n-2);
}
(Java Test harness)
public static void main ( String[] args ) {
for ( int i = 0; i < 10; i++ )
{
System.out.print ( fib(i) +
", " );
}
System.out.println ( fib(10) );
}
(C/C++ Test Harness)
main () {
for ( int i = 0; i < 10; i++ )
{
printf ( "%d, ",
fib(i) );
}
printf ( "%d\n", fib(10)
);
}
Test harness output:
0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55
Example 3: Print out the grade-school multiplication table up to 12x12
Java: (similar for C/C++)
public static void multTables ( int max )
{
for ( int i = 1; i <= max; i++
) {
for ( int j = 1; j <= max;
j++ ) {
System.out.print (
String.format ( "%4d", j * i ));
}
System.out.println();
}
}
Example output:
1 2
3 4 5
6 7 8
9 10 11 12
2
4 6 8
10 12 14
16 18 20
22 24
3
6 9 12
15 18 21
24 27 30
33 36
4
8 12 16
20 24 28
32 36 40
44 48
5
10 15 20
25 30 35
40 45 50
55 60
6
12 18 24
30 36 42
48 54 60
66 72
7
14 21 28
35 42 49
56 63 70
77 84
8
16 24 32
40 48 56
64 72 80
88 96
9
18 27 36
45 54 63
72 81 90 99
108
10
20 30 40
50 60 70
80 90 100 110 120
11
22 33 44
55 66 77
88 99 110 121 132
12
24 36 48
60 72 84 96
108 120 132 144
Example 4: Write a function that sums up integers from a text file, one int per line.
Java:
public static void sumFile ( String name )
{
try {
int total = 0;
BufferedReader in = new
BufferedReader ( new FileReader ( name ));
for ( String s =
in.readLine(); s != null; s = in.readLine() ) {
total += Integer.parseInt
( s );
}
System.out.println ( total );
in.close();
}
catch ( Exception xc ) {
xc.printStackTrace();
}
}
Example 5: Write function to print the odd numbers from 1 to 99.
C/C++:
void printOdds() {
for (int i = 1; i < 100; i +=
2) {
printf ("%d\n", i);
// or cout << i << endl;
}
}
Java:
public static void printOdds() {
for (int i = 1; i < 100; i +=
2) {
System.out.println ( i );
}
}
Example 6: Find the largest int value in an int array.
Java:
public static int largest ( int[] input ) {
int max = Integer.MIN_VALUE;
for ( int i = 0; i < input.length;
i++ ) {
if ( input[i] > max ) max =
input[i];
}
return max;
}
Example 7: Format an RGB value (three 1-byte numbers) as a 6-digit hexadecimal string.
Java:
public String formatRGB ( int r, int g, int
b ) {
return (toHex(r) + toHex(g) +
toHex(b)).toUpperCase();
}
public String toHex ( int c ) {
String s = Integer.toHexString (
c );
return ( s.length() == 1 ) ?
"0" + s : s;
}
Or in Java 1.5:
public String formatRGB ( int r, int g, int
b ) {
return String.format (
"%02X%02X%02X", r, g, b );
}
Example output for (255, 0, 128):
Here are some examples:
Likely classes: a Deck, a Card, a Hand, a Board, and possibly Rank and Suit. Drill down on who‘s responsible for creating new Decks, where they get shuffled, how you deal cards, etc. Do you need a different instance for every card in a casino in Vegas?
Possible sub-issues: do they know the animal kingdom at all? (I.e. common sense.) What properties and methods do they immediately think are the most important? Do they use abstract classes and/or interfaces to represent shared stuff? How do they handle the multiple-inheritance problem posed by, say, a tomato (fruit or veggie?), a sponge (animal or plant?), or a mule (donkey or horse?)
Do they even know what a filesystem is, and what services it provides? Likely classes: Filesystem, Directory, File, Permission. What‘s their relationship? How do you differentiate between text and binary files, or do you need to? What about executable files? How do they model a Directory containing many files? Do they use a data structure for it? Which one, and what performance tradeoffs does it have?
How do they represent tags and content? What about containment relationships? Bonus points if they know that this has already been done a bunch of times, e.g. with DOM. But they still have to describe it.
The following commonly-asked OO design interview questions are probably too involved to be good phone-screen weeders:
A good OO design question can test coding, design, domain knowledge, OO principles, and so on. A good weeder question should probably just target whether they know when to use subtypes, attributes, and containment.
Example Data Structure questions:
1) What are some really common data structures, e.g. in java.util?
2) When would you use a linked list vs. a vector?
3) Can you implement a Map with a tree? What about with a list?
4) How do you print out the nodes of a tree in level-order (i.e. first level, then 2nd level, then 3rd level, etc.)
5) What‘s the worst-case insertion performance of a hashtable? Of a binary tree?
6) What are some options for implementing a priority queue?
[Int Basics] coding & OO questions
标签：des java os io strong for ar art cti
原文地址：http://www.cnblogs.com/chayu3/p/3930102.html
