Duyệt vét - Đệ quy - Quay lui 

http://vn.spoj.com/problems/BONES/ - soution - code 

http://vn.spoj.com/problems/NDCCARD/ - solution - code 

http://vn.spoj.com/problems/VMMTFIVE/ - solution - code

http://vn.spoj.com/problems/C11TRCNT/ - solution - code 

http://vn.spoj.com/problems/PIZZALOC/ - solution - code 

http://vn.spoj.com/problems/BONUS13/ - solution - code 

http://vn.spoj.com/problems/DHLOCK/ - solution - code

http://vn.spoj.com/problems/NKABD/ - solution - code

http://vn.spoj.com/problems/VRATF/ - solution - code

http://www.spoj.com/problems/ARDA1/ - vn - solution - code

http://www.spoj.com/problems/CANDY2/ - vn - solution - code

http://www.spoj.com/problems/PALIN/ - solution - code

http://vn.spoj.com/problems/C11SEQ3/ - solution - code

http://vn.spoj.com/problems/MINCUT/ - solution - code

http://vn.spoj.com/problems/NCOB/ - solution - code 
http://vn.spoj.com/problems/NKLETTER/ - solution - code

http://vn.spoj.com/problems/VMDAOBIT/ - solution

http://vn.spoj.com/problems/ROTATION/ - solution

http://vn.spoj.com/problems/NKNUMFRE/ - solution

http://vn.spoj.com/problems/MYSTERY/ - solution

http://vn.spoj.com/problems/BALLGMVN/ - solution

http://vn.spoj.com/problems/AUCTION/ - solution

http://vn.spoj.com/problems/WCALC/ - solution

http://vn.spoj.com/problems/C11PNUM/ - solution

http://vn.spoj.com/problems/LSTAR/ - solution

http://vn.spoj.com/problems/CSTARS/ - solution

http://vn.spoj.com/problems/DHFUNC/ - solution

http://vn.spoj.com/problems/VMSUBSTR/ - solution

http://vn.spoj.com/problems/VOSRTRI/ - solution

http://vn.spoj.com/problems/VMDAOBIT/ - solution

http://vn.spoj.com/problems/COUNTCBG/ - code

http://vn.spoj.com/problems/HOUSES/ - code