help with search program.
hi,
I am creating a simple search program for a 2-dimensional array. I am using the following boolean, and am not sure how to create the driver to check if a value is inside the array. Any help would be appreciated.
here is my code thus far:
publicclass search
{
int[][] list ={{1,4,55,88},
{7,15,61,91},
{14,89,90,99}};
publicstaticvoid main(String[] args)
{
}
publicboolean contains(int anEntry)
{
boolean found =false;
for (int row = 0; row < 3; row++)
for (int column = 0; column < 5; column++)
{
if (anEntry.equals(list[row][column]))
{
found =true;
}
}
return found;
}
}
[1824 byte] By [
LuckY07a] at [2007-11-26 23:55:45]
What you have seems find, but some enhancements could be made.
public class search
{
int[][] list = {{1,4,55,88},
{7,15,61,91},
{14,89,90,99}};
public static void main(String[] args)
{
}
public boolean contains(int anEntry)
{
boolean found = false;
for (int row = 0; row < list.length; row++)
for (int column = 0; column < list[row].length; column++)
// use the .length instead
// This means it'll work with any
// size of array.
{
if (anEntry.equals(list[row][column]))
{
return true;
//This means the loop will end, and the method returns true
// Why keep looping if the value is found right?
}
}
return found;
}
}
thanks for the help! I am confused as to how to use the BOOLEAN inside the main(). How should I call the boolean method to find a value for example the number 7?
In that case, you'd have to pass another parameter inside of your boolean method header.
One that takes a 2-dimensional array.
Also, make your boolean header say
private static boolean contains(int key, int[][] arrayToSearch)
With this you'll have to change a few things inside of your method "contains"
but it should lead you in the right direction.
Now in main, you can use this method as follows:
if ( contains(3, list) ) //Here we call method contains with our 2 parameters
System.out.println("The list contained the value of 3"); //Print if found
else
System.out.println("The list didn't contain the value of 3"); //print if not found
I made some adjustments, but am getting the following errors when trying to pass the array:
C:\MCS142\Search.java:11: non-static variable list cannot be referenced from a static context
if ( contains(15, list) ) //Here we call method contains with our 2 parameters
^
C:\MCS142\Search.java:11: non-static method contains(int,int[][]) cannot be referenced from a static context
if ( contains(15, list) ) //Here we call method contains with our 2 parameters
^
C:\MCS142\Search.java:24: int cannot be dereferenced
if (anEntry.equals(arrayToSearch[row][column]))
^
3 errors
Tool completed with exit code 1
here is my code:
import java.util.*;
public class Search
{
int[][] list = {{1,4,55,88},
{7,15,61,91},
{14,89,90,99}};
public static void main(String[] args)
{
if ( contains(15, list) ) //Here we call method contains with our 2 parameters
System.out.println("The list contained the value of 15"); //Print if found
else
System.out.println("The list didn't contain the value of 15"); //print if not found
}
public boolean contains(int anEntry, int[][] arrayToSearch)
{
boolean found = false;
for (int row = 0; row < 3; row++)
for (int column = 0; column < 5; column++)
{
if (anEntry.equals(arrayToSearch[row][column]))
{
found = true;
}
}
return found;
}
}
I didn't know what to do so I did the following:
-declared the array 'list' as a STATIC variable.
-created a new object 'a' in main(); >> Search a = new Search();
-converted my INT to a STRING in my for loop so I could use 'equals'.
Does this seem like a logical solution? I have never had to declare an array as static before. Could someone look over my code and let me know if it's ok? tks.
//MCS_142
//Search_Program
/*Program that shows how to search a multidimensional array. The array is
declared as Static so that it can be used in the Static main().
**/
import java.util.*;
public class Search
{
private static int[][] list = {{1,4,55,88},//creates 2-dimensional array 'list'.
{7,15,61,91},
{14,89,90,99}};
public static void main(String[] args)
{
Search a = new Search();
if ( a.contains("99", list) ) //Here we call method contains with our 2 parameters
System.out.println("The list contained the value of 99"); //Print if found
else
System.out.println("The list didn't contain the value of 99"); //print if not found
}
public boolean contains(String anEntry, int[][] arrayToSearch)
{
boolean found = false;
for (int row = 0; row < list.length; row++)
for (int column = 0; column < list[row].length; column++)
{
int temp = arrayToSearch[row][column];//temp variable to hold the integer.
String temp2 = Integer.toString(temp); //convert the temp integer to a String.
if (temp2.equals(anEntry))//uses the String compare the value with our target.
{
found = true;
}
}
return found;
}
}
Message was edited by:
LuckY07
Can someone check out the program I wrote above? For this type of search, involving a multidimensional array, would the big Oh notation be (0)n^2? -I know single array searches are just (0)n, but wasn't sure about 2-dimensional arrays.
