Added 2 solutions

varunu28 · varunu28 · commit cf8dd0db1cda · 2019-12-16T10:20:48.000+05:30
diff --git a/Easy/Convert Binary Number in a Linked List to Integer.java b/Easy/Convert Binary Number in a Linked List to Integer.java
@@ -0,0 +1,29 @@
+/**
+ * Definition for singly-linked list.
+ * public class ListNode {
+ *     int val;
+ *     ListNode next;
+ *     ListNode(int x) { val = x; }
+ * }
+ */
+class Solution {
+  public int getDecimalValue(ListNode head) {
+    int length = getLength(head);
+    int sum = 0;
+    while (head != null) {
+      sum += ((int) Math.pow(2, length - 1)) * head.val;
+      length--;
+      head = head.next;
+    }
+    return sum;
+  }
+  
+  private int getLength(ListNode head) {
+    int count = 0;
+    while (head != null) {
+      count++;
+      head = head.next;
+    }
+    return count;
+  }
+}
diff --git a/Easy/Element Appearing More Than 25% In Sorted Array.java b/Easy/Element Appearing More Than 25% In Sorted Array.java
@@ -0,0 +1,57 @@
+class Solution {
+  public int findSpecialInteger(int[] arr) {
+    int n = arr.length;
+    int oneFourthNum = arr[n / 4];
+    int halfNum = arr[n / 2];
+    int threeFourthNum = arr[3 * n / 4];
+    if(Math.max(n/4, binarySearchRight(arr, 0, n - 1, oneFourthNum)) - 
+       Math.min(n/4, binarySearchLeft(arr, 0, n - 1, oneFourthNum)) >= arr.length / 4) {
+         return oneFourthNum;
+       }
+    if(Math.max(n/2, binarySearchRight(arr, 0, n - 1, halfNum)) - 
+       Math.min(n/2, binarySearchLeft(arr, 0, n - 1, halfNum)) >= arr.length / 4) {
+         return halfNum;
+       }
+    if(Math.max((3 * n)/4, binarySearchRight(arr, 0, n - 1, threeFourthNum)) - 
+       Math.min((3 * n)/4, binarySearchLeft(arr, 0, n - 1, threeFourthNum)) >= arr.length / 4) {
+         return threeFourthNum;
+       }
+    return -1;
+  }
+  
+  private int binarySearchLeft(int[] arr, int start, int end, int num) {
+    int minIdx = Integer.MAX_VALUE;
+    while (start < end) {
+      int mid = (start + end) / 2;
+      if (arr[mid] == num) {
+        minIdx = Math.min(mid, minIdx);
+        end = mid - 1;
+      }
+      else if (arr[mid] < num) {
+        start = mid + 1;
+      }
+      else {
+        end = mid - 1;
+      }
+    }
+    return minIdx;
+  }
+  
+  private int binarySearchRight(int[] arr, int start, int end, int num) {
+    int maxIdx = Integer.MIN_VALUE;
+    while (start < end) {
+      int mid = (start + end) / 2;
+      if (arr[mid] == num) {
+        maxIdx = Math.max(mid, maxIdx);
+        start = mid + 1;
+      }
+      else if (arr[mid] < num) {
+        start = mid + 1;
+      }
+      else {
+        end = mid - 1;
+      }
+    }
+    return maxIdx;
+  }
+}
