fix Two Sum bug
Update chapTree.tex

Unique Binary SearchTrees 时间复杂度O(n^2)
Merge pull request #13 from gaodayue/master

fix Two Sum bug
Merge pull request #14 from x1957/master

Update chapTree.tex
Merge pull request #12 from advancedxy/master

为longest consecutive sequence增加了一个worst case为O(n)的解法
修复可能越界的bug
rename leetcode题解(C++版).pdf to leetcode-cpp.pdf
Merge branch 'master' of github.com:sunwaylive/leetcode-1 into sunwaylive-master
update document
fix url
fix atoi