I have searched on internet about implementation of Segment trees but found nothing when it came to lazy propagation. There were some previous questions on stack overflow but th
Here's the link. It has an implementation and explanation of segment tree with lazy propagation. Although the code is in Java but it won't matter because there are only two functions 'update' and 'query' and both of them are array based. So these functions would work in C and C++ also without any modification.
http://isharemylearning.blogspot.in/2012/08/lazy-propagation-in-segment-tree.html