Algo’s 2c

http://www.geeksforgeeks.org/sort-an-array-of-0s-1s-and-2s/
http://www.geeksforgeeks.org/backtracking-set-3-n-queen-problem/
http://www.geeksforgeeks.org/dynamic-programming-set-32-word-break-problem/

http://www.geeksforgeeks.org/write-a-c-program-that-given-a-set-a-of-n-numbers-and-another-number-x-determines-whether-or-not-there-exist-two-elements-in-s-whose-sum-is-exactly-x/ – (see 2nd solution using hashmap, O(n) solution).

http://www.programcreek.com/2012/12/add-two-numbers/