diff --git a/Searching/Find Smallest Letter Greater Than Target.java b/Searching/Find Smallest Letter Greater Than Target.java
new file mode 100644
index 0000000..e808aa8
--- /dev/null
+++ b/Searching/Find Smallest Letter Greater Than Target.java	
@@ -0,0 +1,21 @@
+class Solution
+{
+public char nextGreatestLetter(char[] letters, char target)
+    {
+        int start = 0, end = letters.length - 1;
+
+        while (start <= end)
+        {
+            int mid = start + (end - start) / 2;
+            if (target < letters[mid])
+            {
+                end = mid - 1;
+            }
+            else
+            {
+                start = mid + 1;
+            }
+        }
+        return letters[start % letters.length];
+    }
+}
\ No newline at end of file
diff --git a/Searching/Search in Rotated Sorted Array.java b/Searching/Search in Rotated Sorted Array.java
new file mode 100644
index 0000000..9620cc5
--- /dev/null
+++ b/Searching/Search in Rotated Sorted Array.java	
@@ -0,0 +1,37 @@
+class Solution
+{
+public int search(int[] nums, int target)
+    {
+        int left = 0, right = nums.length - 1, mid;
+        while (left <= right)
+        {
+            mid = left + (right - left) / 2;
+            if (nums[mid] == target)
+                return mid;
+            // condition for left side is sort
+            if (nums[left] <= nums[mid])
+            {
+                if (target >= nums[left] && target <= nums[mid])
+                {
+                    right = mid - 1;
+                }
+                else
+                {
+                    left = mid + 1;
+                }
+            }
+            else
+            {
+                if (target >= nums[mid] && target <= nums[right])
+                {
+                    left = mid + 1;
+                }
+                else
+                {
+                    right = mid - 1;
+                }
+            }
+        }
+        return -1;
+    }
+}
\ No newline at end of file
diff --git a/Searching/Sum of Square Numbers.java b/Searching/Sum of Square Numbers.java
new file mode 100644
index 0000000..5a9cdb6
--- /dev/null
+++ b/Searching/Sum of Square Numbers.java	
@@ -0,0 +1,16 @@
+class Solution {
+    public boolean judgeSquareSum(int c) {
+        for (int i = 2; i * i <= c; i++) {
+            int count = 0;
+            if (c % i == 0) {
+                while (c % i == 0) {
+                    count++;
+                    c /= i;
+                }
+                if (i % 4 == 3 and count % 2 != 0)
+                    return false;
+            }
+        }
+        return c % 4 != 3;
+    }
+}
\ No newline at end of file