Update README.md

Author: skjha1

README.md

@@ -63,11 +63,12 @@
   - [23 Finding Duplicate in Soorted Array](https://github.com/skjha1/Data-Structure-Algorithm/blob/master/Array/23%20Finding%20Duplicate%20in%20Soorted%20Array.cpp)
   - [24 Counting Duplicate Elements In Sorted M2](https://github.com/skjha1/Data-Structure-Algorithm/blob/master/Array/24%20Counting%20Duplicate%20Elements%20In%20Sorted.cpp)
   - [25 Counting Duplicate elements using hash table (SA)](https://github.com/skjha1/Data-Structure-Algorithm/blob/master/Array/25%20Counting%20Duplicate%20elements%20using%20hash%20table%20(SA).cpp)
-  - [26 Finding Duplicate in Unsoorted Array](https://github.com/skjha1/Data-Structure-Algorithm/blob/master/Array/26%20Finding%20Duplicate%20in%20Unsoorted%20Array.cpp)
-  - [27 Find a pair with sum k](https://github.com/skjha1/Data-Structure-Algorithm/blob/master/Array/27%20Find%20a%20pair%20with%20sum%20k.cpp)
-  - [28 Find a pair with sum k in unsorted](https://github.com/skjha1/Data-Structure-Algorithm/blob/master/Array/28%20Find%20a%20pair%20with%20sum%20k%20in%20unsorted.cpp)
-  - [29 Find a pair with sum k using Hashing](https://github.com/skjha1/Data-Structure-Algorithm/blob/master/Array/29%20Find%20a%20pair%20with%20sum%20k%20using%20Hashing.cpp)
-  - [30 Finding max & min in single scan](https://github.com/skjha1/Data-Structure-Algorithm/blob/master/Array/30%20Finding%20max%20%26%20min%20in%20single%20scan.cpp)
+  - [26 Counting Duplicate elements using hash table (USA)](https://github.com/skjha1/Data-Structure-Algorithm/blob/master/Array/25%20b.%20Find%20Duplicate%20in%20unsorted%20array%20using%20hash%20table.cpp)
+  - [27 Finding Duplicate in Unsoorted Array](https://github.com/skjha1/Data-Structure-Algorithm/blob/master/Array/26%20Finding%20Duplicate%20in%20Unsoorted%20Array.cpp)
+  - [28 Find a pair with sum k](https://github.com/skjha1/Data-Structure-Algorithm/blob/master/Array/27%20Find%20a%20pair%20with%20sum%20k.cpp)
+  - [29 Find a pair with sum k in unsorted](https://github.com/skjha1/Data-Structure-Algorithm/blob/master/Array/28%20Find%20a%20pair%20with%20sum%20k%20in%20unsorted.cpp)
+  - [30 Find a pair with sum k using Hashing](https://github.com/skjha1/Data-Structure-Algorithm/blob/master/Array/29%20Find%20a%20pair%20with%20sum%20k%20using%20Hashing.cpp)
+  - [31 Finding max & min in single scan](https://github.com/skjha1/Data-Structure-Algorithm/blob/master/Array/30%20Finding%20max%20%26%20min%20in%20single%20scan.cpp)
       - [Problems on array](https://github.com/skjha1/Data-Structure-Algorithm/tree/master/Array/Problems)
 * [:blue_book:](https://drive.google.com/drive/folders/1VzrX63lw2w44Vr3WL8udBO5Cyc3-W5vc) [String](https://github.com/skjha1/Data-Structure-Algorithm/tree/master/String)
    - [01 Length of string](https://github.com/skjha1/Data-Structure-Algorithm/blob/master/String/01%20Length%20of%20string.cpp)