B+ Tree Implementation in C http://www.amittai.com/prose/bpt.c
permutations string len 9: execution time: 0.045s permutations string len 10: execution time: 0.403s permutations string len 11: execution time: 4.336s
2500x2500 nested loop execution time is only: 0.058s 12000x12000 nested loop execution time is : 1.2s