Please study the following problems related to sorting.
1.
http://acm.uva.es/p/v2/270.html
2.
http://acm.uva.es/p/v2/299.html
3.
http://acm.uva.es/p/v4/482.html
4.
http://acm.uva.es/p/v6/612.html
5.
http://acm.uva.es/p/v7/755.html
6.
http://acm.uva.es/p/v100/10041.html
7.
http://acm.uva.es/p/v100/10057.html
8.
http://acm.uva.es/p/v100/10062.html
9.
http://acm.uva.es/p/v101/10107.html
10.
http://acm.uva.es/p/v101/10152.html
11.
http://acm.uva.es/p/v101/10194.html
12.
http://acm.uva.es/p/v103/10327.html