i did DQUERY problem in spoj----link http://www.spoj.com/problems/DQUERY/

this is my solution...after referring through some material and blog AND finally got AC....

http://ideone.com/8qZj1Z

but ...could any one pls explain what happened between (53-72) lines....i couldnt understand....

pls explain it clearly so tht a beginner of this ALGO could understand.....also pls say if we can write those lines without any confusion if possible..

i would be very thankful to you....

thank you..