Test cases are failing in the following codes

#1

STRING IS PALINDROME
QUESTION : https://hack.codingblocks.com/app/contests/1211/503/problem
CODE : https://ide.codingblocks.com/s/253557

ARRAY TARGET SUM TRIPLETS
QUESTION : https://hack.codingblocks.com/app/contests/1211/195/problem
CODE : https://ide.codingblocks.com/s/253559

STRING REMOVE DUPLICATES
QUESTION : https://hack.codingblocks.com/app/contests/1211/1369/problem
CODE : https://ide.codingblocks.com/s/253561

#2
#3

refer this for logic

#4