new files

Task/Binary-search/Java/binary-search-1.java

@@ -0,0 +1,27 @@
+...
+//check will be the number we are looking for
+//nums will be the array we are searching through
+public static int binarySearch(int[] nums, int check){
+        int hi = nums.length - 1;
+        int lo = 0;
+        while(hi >= lo){
+                guess = lo + ((hi - lo) / 2);
+                if(nums[guess] > check){
+                        hi = guess - 1;
+                }else if(nums[guess] < check){
+                        lo = guess + 1;
+                }else{
+                        return guess;
+                }
+        }
+        return -1;
+}
+
+public static void main(String[] args){
+        int[] searchMe;
+        int someNumber;
+        ...
+        int index = binarySearch(searchMe, someNumber);
+        System.out.println(someNumber + ((index == -1) ? " is not in the array" : (" is at index " + index)));
+        ...
+}

Task/Binary-search/Java/binary-search-2.java

@@ -0,0 +1,21 @@
+public static void main(String[] args){
+        int[] searchMe;
+        int someNumber;
+        ...
+        int index = binarySearch(searchMe, someNumber, 0, searchMe.length);
+        System.out.println(someNumber + ((index == -1) ? " is not in the array" : (" is at index " + index)));
+        ...
+}
+
+public static int binarySearch(int[] nums, int check, int lo, int hi){
+        if(hi < lo){
+                return -1; //impossible index for "not found"
+        }
+        int guess = (hi + lo) / 2;
+        if(nums[guess] > check){
+                return binarySearch(nums, check, lo, guess - 1);
+        }else if(nums[guess]<check){
+                return binarySearch(nums, check, guess + 1, hi);
+        }
+        return guess;
+}

Task/Binary-search/Java/binary-search-3.java

@@ -0,0 +1,8 @@
+import java.util.Arrays;
+
+int index = Arrays.binarySearch(array, thing);
+int index = Arrays.binarySearch(array, startIndex, endIndex, thing);
+
+// for objects, also optionally accepts an additional comparator argument:
+int index = Arrays.binarySearch(array, thing, comparator);
+int index = Arrays.binarySearch(array, startIndex, endIndex, thing, comparator);

Task/Binary-search/Java/binary-search-4.java

@@ -0,0 +1,4 @@
+import java.util.Collections;
+
+int index = Collections.binarySearch(list, thing);
+int index = Collections.binarySearch(list, thing, comparator);