Binary-Search-2

First&LastSortedArray.java

@@ -0,0 +1,33 @@
+class Solution {
+    public int[] searchRange(int[] nums, int target) {
+        int left = 0;
+        int right=nums.length;
+        int[] pos = {-1,-1};
+        while(left<right)
+        {
+            int mid = (left+right)/2;
+            if(target>nums[mid])
+            {
+                left = left+1;
+            }
+            else if (target < nums[mid])
+            {
+                right=right-1;
+            }
+            else
+            {
+                left = mid;
+                right=mid;
+                while(left>=0 && nums[left]==target)
+                left=left-1;
+                while(right<nums.length && nums[right]==target)
+                right++;
+                pos[0]=left+1;
+                pos[1]=right-1;
+                return pos;
+            }
+        }
+        return pos;
+
+    }
+}

MinimumRotatedSortedArray.java

@@ -0,0 +1,43 @@
+class Solution {
+    public int findMin(int[] nums) {
+
+        //Binary serach Algorithm.
+
+        if(nums.length==1){
+            return nums[0];
+        }
+        int left = 0, right = nums.length-1;
+
+
+         if(nums[0] < nums[right]){
+
+             return nums[0];
+
+         }
+
+        while(left < right){
+            int mid = left + (right-left)/2;
+
+             if(nums[mid]> nums[mid+1]){
+                return nums[mid+1];
+            }
+
+            if( nums[mid-1] > nums[mid]){
+                return nums[mid];
+            }
+
+
+
+            if(nums[mid] > nums[0]){
+                left = mid+1;
+            }
+
+            else{
+                right = mid-1;
+            }
+        }
+
+        return 0;
+
+    }
+}

PeakElement.java

@@ -0,0 +1,17 @@
+class Solution {
+    public int findPeakElement(int[] nums) {
+        int left = 0;
+        int right = nums.length - 1;
+
+        while (left < right) {
+            int mid = (left + right) / 2;
+            if (nums[mid] > nums[mid + 1]) {
+                right = mid;
+            } else {
+                left = mid + 1;
+            }
+        }
+
+        return left;        
+    }
+}