One Test case is failing

#1

https://ide.codingblocks.com/s/51696
https://hack.codingblocks.com/contests/c/537/63

please tell what is wrong in this code???
if i increase the value of n,it shows run error and if not it shows wrong answer.

#2

take loop variables (i,j) as long long int since you are calculating j=ii ang j=2i+j and i and j can be as large as pow(10,6) therefore take it as long long inside the loop.