CIS 3020 Part 7 - Revision history

Jka: /* CIS 3020 Part 8 */

2007-04-26T21:23:52Z

CIS 3020 Part 8

2007-04-26T21:23:39Z

Array Searching

2007-04-26T21:13:59Z

Array Searching

2007-04-26T21:08:36Z

Code

2007-04-26T20:43:14Z

Problem

2007-04-26T19:04:15Z

Problem

2007-04-26T18:21:24Z

Arrays

2007-04-26T17:16:37Z

Arrays

2007-04-26T17:16:15Z

String Reversal

2007-04-26T16:41:08Z

String Reversal

@@ Line 232: / Line 232: @@
+}
 </pre>
-==CIS 3020 Part 8==
+==[[CIS 3020 Part 8]]==

← Older revision		Revision as of 21:23, 26 April 2007
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	## If next value is larger or equal, make it the largest so far		## If next value is larger or equal, make it the largest so far
	## If next value is smaller, repeat		## If next value is smaller, repeat
		+	===Code===
		+	<pre>
		+	public int posOfLargest(int[] a, int pol, int index) {
		+	int result;
		+	if (index >= a.length) {
		+	result = pol;
		+	} else if (a[pol] > a[index]) {
		+	result = posOfLargest(a, pol, index+1);
		+	} else {
		+	result = posOfLargest(a, index, index+1);
		+	}
		+	return result;
		+	}
		+	</pre>
		+	==CIS 3020 Part 8==

← Older revision		Revision as of 21:13, 26 April 2007
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	* Suppose that we want to know the position of the largest value in an array (the last position, if multiple occurrences)		* Suppose that we want to know the position of the largest value in an array (the last position, if multiple occurrences)
	* We could search linearly to find it		* We could search linearly to find it
		+	* Possible approach:
		+	# Assume value in position 0 is largest
		+	# Compare to next value:
		+	## If no more values, done
		+	## If next value is larger or equal, make it the largest so far
		+	## If next value is smaller, repeat

← Older revision		Revision as of 21:08, 26 April 2007
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	}		}
	</pre>		</pre>
		+	===Array of Arrays===
		+	* It is possible to construct arrays with multiple dimensions:
		+	int[][] a = {{1,2,3},{4,5,6},{7,8,9}};
		+	* Alternative way to declare:
		+	int[][] a = new int[3][];
		+	a[0] = new int[3];
		+	a[1] = new int[3];
		+	a[2] = new int[3];
		+	a[0][0] = 1;
		+	a[0][1] = 2;
		+	a[0][2] = 3;
		+	a[1][0] = 4;
		+	...
		+	* Note: Each row can be a different length
		+	==Array Searching==
		+	* Suppose that we want to know the position of the largest value in an array (the last position, if multiple occurrences)
		+	* We could search linearly to find it

← Older revision		Revision as of 20:43, 26 April 2007
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	## Recur with index plus one		## Recur with index plus one
	## Compute and return sum of the element at index and recursive's returned value		## Compute and return sum of the element at index and recursive's returned value
		+	===Code===
		+	<pre>
		+	class ArraySum {
		+	public int elementSum(int[] a) {
		+	return doElementSum(a, 0);
		+	}
		+
		+	private int doElementSum(int[] a, int index) {
		+	int sum;
		+	if (a.length <= index) {
		+	sum = 0;
		+	} else {
		+	sum = a[index] + doElementSum(a, index+1);
		+	}
		+	return sum;
		+	}
		+	}
		+	</pre>

← Older revision		Revision as of 19:04, 26 April 2007
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	** Assumptions: Array does not change		** Assumptions: Array does not change
	** Relationships: none		** Relationships: none
		+	* Design:
		+	** Given an array, the array's length, index of current element
		+	# If array's length is less than or equal to the index then return zero
		+	# Otherwise
		+	## Recur with index plus one
		+	## Compute and return sum of the element at index and recursive's returned value

← Older revision		Revision as of 18:21, 26 April 2007
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	iArray = new int[3]; // creates actual array & assigns it to iArray		iArray = new int[3]; // creates actual array & assigns it to iArray
	</pre>		</pre>
		+	===Problem===
		+	* Compute the sum of the elements in an int valued array
		+	* Analysis:
		+	** Inputs: an array of int values
		+	** Outputs: An integer of the sum of all values
		+	** Constraints: None
		+	** Assumptions: Array does not change
		+	** Relationships: none

@@ Line 157: / Line 157: @@
 * Creation:
   ''typeOfValue''[] ''referenceVar'';
-  ''reverenceVar'' = new ''typeOfValue''[''size''];
+  ''referenceVar'' = new ''typeOfValue''[''size''];
 * Example:
 <pre>

@@ Line 147: / Line 147: @@
    return result;
+}
 </pre>

@@ Line 130: / Line 130: @@
 # Reverse the rest of the string
 # Add the first character to the end
-** This defines our recursive case
+* This defines our recursive case