The only reason I can think of -
Weak test cases (lengths of required(valid) triangle were very close to r) i.e. number of queries giving required triangle in less number of iterations >> number of queries giving required triangle in more number of iterations
Ah, yes the intended solution uses something different too. Its a cross between a segtree and a merge sort tree. Thanks for describing the intended one. 
https://www.codechef.com/viewsolution/17834749
@kailashnath199 Thank you Man. Now, i am able to do this question using segment tree.
Thank You.
Please can someone explain to me the math involved behind the limiting the value of K to 50 ?
can anyone just tell me how setter is doing without sorting nodes.
Please can someone help me in improving my solution. I have understood the concept and written a code but it is giving TLE.The complexity is Q.K.log n where k = 45. here is my code Thanks