From 47a3b64203c1649eb9a5e242a866df43ec71d3ff Mon Sep 17 00:00:00 2001
From: Chris Koeritz <fred@gruntose.com>
Date: Tue, 3 Jan 2017 01:21:18 -0500
Subject: [PATCH] new example code

---
 .../algorithms/SubstringFinder.java           | 76 +++++++++++++++++++
 nucleus/library/algorithms/sorts.h            |  6 +-
 2 files changed, 79 insertions(+), 3 deletions(-)
 create mode 100644 kona/src/org/feistymeow/algorithms/SubstringFinder.java

diff --git a/kona/src/org/feistymeow/algorithms/SubstringFinder.java b/kona/src/org/feistymeow/algorithms/SubstringFinder.java
new file mode 100644
index 00000000..4e568b67
--- /dev/null
+++ b/kona/src/org/feistymeow/algorithms/SubstringFinder.java
@@ -0,0 +1,76 @@
+package org.feistymeow.algorithms;
+
+/**
+ * used to find strings in other strings.
+ *
+ * part of google interview prep.
+ */
+
+public class SubstringFinder
+{
+
+	/**
+	 * returns the position of 'x' in 'y', or returns a negative number.
+	 */
+	public int findXinY(String x, String y)
+	{
+		if ((x == null) || (y == null))
+			return -1; // nulls are invalid to compare.
+		if (y.length() < x.length())
+			return -1; // x cannot be found in shorter string.
+		for (int yIter = x.length() - 1; yIter < y.length(); yIter++) {
+			boolean good = true;
+			/*
+			 * xIter has to start at valid value in x, and that needs to be at end of x. board actually had uncorrected error here, where
+			 * xIter started at yIter, which is really wrong.
+			 */
+			// simplified xIter which was inducing all sorts of OBOBs. even though i found the end in yIter,
+			// i go forwards on xIter.
+			for (int xIter = 0; xIter < x.length(); xIter++) {
+				int yComparePosition = (yIter - x.length() + 1) + xIter;
+				if (x.charAt(xIter) != y.charAt(yComparePosition)) {
+					// System.out.println("no match -- y[" + yIter + "]=" + y.charAt(yPosn) + " x[" + xIter + "]=" + x.charAt(xIter));
+					good = false;
+					break;
+				}
+			}
+			if (good) {
+				int toReturn = yIter - x.length() + 1;
+				// System.out.println("found at position " +toReturn );
+				return toReturn;
+			}
+		}
+
+		return -1;
+	}
+
+	public static void main(String[] argv)
+	{
+		SubstringFinder sf = new SubstringFinder();
+
+		String x1 = "petunia";
+		String y1 = "sometimes my flowers are roses and sometimes they are petunias and sometimes they are turnips.";
+		if (sf.findXinY(x1, y1) != 54) {
+			System.out.println("FAILURE: did not find at right index for test 1");
+		} else {
+			System.out.println("OKAY: found substring at right index for test 1");
+		}
+
+		String x2 = "qn";
+		String y2 = "xaqno";
+		if (sf.findXinY(x2, y2) != 2) {
+			System.out.println("FAILURE: did not find at right index for test 2");
+		} else {
+			System.out.println("OKAY: found substring at right index for test 2");
+		}
+
+		String x3 = "qn";
+		String y3 = "xaqon";
+		if (sf.findXinY(x3, y3) >= 0) {
+			System.out.println("FAILURE: found non-existent string for test 3");
+		} else {
+			System.out.println("OKAY: did not find substring for test 3");
+		}
+
+	}
+}
diff --git a/nucleus/library/algorithms/sorts.h b/nucleus/library/algorithms/sorts.h
index 592f9903..c6e21abe 100644
--- a/nucleus/library/algorithms/sorts.h
+++ b/nucleus/library/algorithms/sorts.h
@@ -266,9 +266,9 @@ namespace algorithms {
 		}
 
 	private:
-		bool _reverse = false;  // is the sorting in reverse?
-		int _total = 0;
-		int *_heapspace = NULL_POINTER;
+		bool _reverse;  // is the sorting in reverse?
+		int _total;  // how many total elements are there?
+		int *_heapspace;  // track a pointer to the array.
 	};
 
 	/*!
-- 
2.34.1