Initial commit
problem 1
Problem 2 naive solution
solve Problem 3 elegantly
add function isPalindsome
solve it by brute force
add time cost in Promblem#4, slove Problem#5 by half brute force
solve Problem#6 elegantly
solve Problem#7
solve Problem#9 by brute force
solve Problem#10 by BF. isPrime use sqrt
solve Problem#8 by BF
solve Problem#12 by BF, calculate factors by sqrt
solve Problem#14 by BF, good
solve Problem#11 by BF, debug version
calculate BIG NUMBER using ARRAY by BF
Merge branch 'master' of https://github.com/python27/ProjectEuler
Solve Problem#20 by BF, elegant
solve it by BF, BIG NUMBER using ARRAY, good
revise the bug, size_t expression always return postive number