reorganizing code

Author: Algorithmica

2018-feb/divide-and-prune/src/com/alg/top20/divideprune/CountOnes.java

@@ -0,0 +1,26 @@
+package com.alg.top20.divideprune;
+
+
+public class CountOnes {
+
+	public static int countOnes(int[] in) {
+		int left = 0, right = in.length - 1;
+		if (in.length == 0 ||
+				in[left] == 0)
+			return 0;
+		while (left < right) {
+			int mid = (int) Math.ceil(left + (right - left) >>> 1);
+			if (in[mid] == 1)
+				left = mid;
+			else
+				right = mid - 1;
+		}
+		return right + 1;
+	}
+
+	public static void main(String[] args) {
+		// TODO Auto-generated method stub
+
+	}
+
+}

2018-feb/adhoc-thinking/src/com/alg/top20/adhoc/MatrixSearch.java renamed to 2018-feb/divide-and-prune/src/com/alg/top20/divideprune/MatrixSearch.java

@@ -1,4 +1,5 @@
-package com.alg.top20.adhoc;
+package com.alg.top20.divideprune;
+
 
 import java.util.Arrays;
 
@@ -35,7 +36,7 @@ public static boolean matrixSearch3(int[][] in, int target) {
 		int left = 0, right = n * m - 1;
 
 		while (left <= right) {
-			int mid = (left + right) / 2;
+			int mid = left + (right-left)>>>1;
 			int element = in[mid / n][mid % n];
 			if (element == target)
 				return true;

2018-feb/divide-and-prune/src/com/alg/top20/divideprune/MinInRotatedSortedArray.java

@@ -0,0 +1,23 @@
+package com.alg.top20.divideprune;
+
+
+public class MinInRotatedSortedArray {
+
+	public static int findMin(int[] in) {
+		int left = 0, right = in.length - 1;
+		
+		while (left < right) {
+			int mid = left + (right - left) >>> 1;
+			if (in[mid] > in[right])
+				left = mid + 1;
+			else
+				right = mid;
+		}
+		return in[right];
+	}
+	public static void main(String[] args) {
+		// TODO Auto-generated method stub
+
+	}
+
+}