Complete Problem 6

Problem6.java

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+// Time Complexity : O(log N)
+// Space Complexity : O(1)
+// Did this code successfully run on Leetcode : Yes
+// Any problem you faced while coding this : No
+
+class Solution {
+    public int search(int[] nums, int target) {
+        int left = 0;
+        int right = nums.length -1;
+
+        // Use the Binary Search approach since we need to solve this in O(log N)
+        // Even though the array is rotated we always know that one half will be always sorted
+        while (left <= right) {
+            // Identigy the mid
+            int mid = left + (right - left)/2;
+
+            //return is mid is the target
+            if (nums[mid] == target) return mid;
+
+            //check if left half is sorted
+            if (nums[left] <= nums[mid]) {
+                //check if the left half is sorted
+                if (target >= nums[left] && target < nums[mid]) {
+                    //search left half
+                    right = mid - 1;                
+                } else {
+                    // search right half
+                    left = mid + 1;
+                }
+            } else {
+                //check if the right half is sorted
+                if (target <= nums[right] && target > nums[mid]) {
+                    //search right half
+                    left = mid + 1;
+                } else {
+                    //search left half
+                    right = mid - 1;
+                }
+            }
+        }
+
+        return -1;
+    }
+}

Problem7.java

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+// Time Complexity : O(log N)
+// Space Complexity : O(1)
+// Did this code successfully run on Leetcode : Yes
+// Any problem you faced while coding this : No
+
+class Solution {
+    public int search(ArrayReader reader, int target) {
+        int low = 0
+        int high = 1;
+
+        while (reader.get(high) < target) {
+            low = high;
+            high = high * 2;
+        }
+
+        while(low <= high) {
+            int mid = low + (high - low)/2;
+            if (reader.get(mid) == targer) return mid;
+            if (reader.get(mid) > target) {
+                high = mid - 1;
+            } else {
+                low = mid + 1;
+            }
+        }
+
+        return -1;
+    }
+}

Problem8.java

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+// Time Complexity : O(log m*n)
+// Space Complexity : O(1)
+// Did this code successfully run on Leetcode : Yes
+// Any problem you faced while coding this : No
+
+class Solution {
+    public boolean searchMatrix(int[][] matrix, int target) {
+        int m = matrix.length;
+        int n = matrix[0].length;
+
+        int low = 0; int high = m*n-1;
+
+        while (low <= high) {
+            int mid = low + (high - low) / 2;
+
+            int r = mid / n;
+            int c = mid % n;
+
+            if (matrix[r][c] == target) return true;
+
+            if (matrix[r][c] > target) {
+                high = mid - 1;
+            } else {
+                low = mid + 1;
+            }
+        }
+        return false;
+    }
+}