1 test case failed

#1

link of problem - https://hack.codingblocks.com/contests/c/537/58
my code - https://ide.codingblocks.com/s/33275
it is showing one test case fails … i am not able to understand where am i gone wrong?
please help me to solve this.

#2

https://ide.codingblocks.com/s/33309

i have corrected your code and added required comments.