BinarySearch01

SearchInSortedArrayOfUnknownSize.java

@@ -0,0 +1,23 @@
+class SearchInSortedArrayOfUnknownSize {
+    public int search(ArrayReader reader, int target) {
+        int low=0;
+        int high=1;
+        while(reader.get(high)<target){
+            low=high;
+            high=2*high;
+        }
+        while(low <=high){
+            int mid=low+(high-low)/2;
+            if(reader.get(mid)==target){
+                return mid;
+            }
+            if(reader.get(mid)>target){
+                high=mid-1;
+            }else{
+                low=mid+1;
+            }
+
+        }
+        return -1;
+    }
+}

SearchMatrixWithSortedRowsAndCols.java

@@ -0,0 +1,21 @@
+public class SearchMatrixWithSortedRowsAndCols {
+    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;
+            else if(matrix[r][c]>target){
+                high=mid-1;
+            }else{
+                low=mid+1;
+            }
+        }
+        return false;
+    }
+
+}

SearchRotatedSortedArray.java

@@ -0,0 +1,33 @@
+//LC33
+class SearchRotatedSortedArray {
+    public int search(int[] nums, int target) {
+        int low=0;
+        int high=nums.length-1;
+
+        if(high==0 || nums==null)
+            return -1;
+        while(low<=high){
+            int mid= low+(high-low)/2;
+
+            if(nums[mid]==target){
+                return mid;
+            }else{
+                if(nums[low]<=nums[mid]){//left half is sorted
+                    if(nums[low]<=target && nums[mid]>target){
+                        high=mid-1;
+                    }else{
+                        low=mid+1;
+                    }
+                }else{
+                    if(nums[mid]<target && nums[high]>=target){
+                        low=mid+1;
+                    }else{
+                        high=mid-1;
+                    }
+                }
+            }
+        }
+        return -1;
+    }
+
+}