I think you can add something on how to avoid those leading zeroes. I was simple printing the array and wasted A HUGE CHUNK of my time because it was printing leading 0.
And BTW, I feel the problem statement SHOULD specify that leading zeroes arent allowed. I mean, yeah, to many people “5555+5555=0000” would make sense.
The logic of your code isn’t clear to me. Can you elaborate??
Agreed
That ought to be the case, but i thought of real life calculators, which never print 0000. Maybe the author’s calculator wasn’t that faulty to print 0000. 
Mate, in his solution, that matters not.
Because he used the condition a>0 || b > 0
If one of them is zero, it will be automatically ignored.
for each i erased character at that place…
And checked the string so formed is divisble by 6 or not
check condition in O(1)
condition:
1.check even or not
2.if yes check (sum-a[i])%3 or not
I think it’s just because erase giving Tle
Possible XD. Imagine my reaction when I opened comment section after 20min only to realzie that leading zeroes are giving WA. I was like, “… (xinfinity)XDXD”
hey taran can u share your fb profile link or can you send me req.? Needed to talk to you personally. 
Your code can only delete 3,6 and 9 from given number due to line
if(p%3==0)
Further, no need to check sum%3==0
Simply check (sum-d)%3==0 where d is the deleted digit.
As far as i know about c++, String s = p itself takes Linear time, making your solution time out.
How Come??
Surely you can ask anything here mate…
Happens Mate…
I see you haven’t participated in lunchtime…
Ask away mate…
t = int(input())
while t>0 :
n = input()
i = len(n)
flag = 0
li = []
while i>0:
copy = int(n[:i-1] + n[i:])
if copy%6 == 0:
li.append(copy)
flag = 1
i -= 1
if flag == 1:
print(str(max(li)).rjust(len(n)-1, "0"))
else:
print("-1")
t = t-1
I don’t know why it was giving TLE although you have also used nested loops and hence O(n^2)… please help me?
I did use two loops but not two nested loops. There’s a difference. Nested loop is loop within a loop, which i haven’t used and you have.
That’s what that make the difference.
@taran_1407 the very first solution that passed is O(N^2)! Can you please look at his code and please comment that whether the test cases are weak or he has made some optimization ?
@soham1234 https://www.codechef.com/viewsolution/16001805
just remove the line where you have checked the value of p and AC
the idea is that when you get the value lesser, in the position nearer to the units place it will lead to better solution than that in the higher digits !