Binary Search 2 Probelms

FindMin.java

@@ -0,0 +1,25 @@
+class FindMin {
+    public int findMin(int[] nums) {
+
+        int low = 0, high = nums.length - 1, mid;
+
+        while(low <= high) {
+            mid = low + (high - low) / 2;
+
+            if(nums[low] <= nums[high]) return nums[low];
+
+            if((mid == low || nums[mid] < nums[mid - 1])
+                    && (mid == high || nums[mid] < nums[mid + 1]))
+                return nums[mid];
+
+            if(nums[mid] >= nums[low]) {
+                low = mid + 1;
+            } else {
+                high = mid - 1;
+            }
+
+        }
+
+        return -1;
+    }
+}

FindPeakElement.java

@@ -0,0 +1,19 @@
+class FindPeakElement {
+    public int findPeakElement(int[] nums) {
+
+        int low = 0, high = nums.length - 1, mid;
+
+        while(low <= high) {
+            mid = low + (high - low) / 2;
+
+            if((mid == low || nums[mid] > nums[mid - 1]) && (mid == high || nums[mid] > nums[mid+1])) {
+                return mid;
+            } else if(nums[mid] < nums[mid + 1]) {
+                low = mid + 1;
+            } else {
+                high = mid - 1;
+            }
+        }
+        return -1;
+    }
+}

SearchRange.java

@@ -0,0 +1,52 @@
+class SearchRange {
+    public int[] searchRange(int[] nums, int target) {
+        if(nums.length == 0 || target < nums[0] || target > nums[nums.length - 1]) return new int[]{-1,-1};
+        int first = getFirstOccurance(nums, target, 0, nums.length - 1);
+        if(first == -1) return new int[]{-1,-1};
+
+        int last = getLastOccurance(nums, target, first, nums.length - 1);
+        return new int[] {first, last};
+    }
+
+    private int getFirstOccurance(int[] nums, int target, int low, int high) {
+        int mid;
+
+        while(low <= high) {
+            mid = low + (high - low) / 2;
+
+            if(nums[mid] ==  target) {
+                if(mid ==  low || nums[mid-1] != nums[mid]) {
+                    return mid;
+                } else {
+                    high = mid - 1;
+                }
+            } else if(nums[mid] > target) {
+                high = mid - 1;
+            } else {
+                low = mid + 1;
+            }
+        }
+        return -1;
+    }
+
+    private int getLastOccurance(int[] nums, int target, int low, int high) {
+        int mid;
+
+        while(low <= high) {
+            mid = low + (high - low) / 2;
+
+            if(nums[mid] ==  target) {
+                if(mid ==  high || nums[mid+1] != nums[mid]) {
+                    return mid;
+                } else {
+                    low = mid + 1;
+                }
+            } else if(nums[mid] > target) {
+                high = mid - 1;
+            } else {
+                low = mid + 1;
+            }
+        }
+        return -1;
+    }
+}