Dutch National Flag Problem.

Re-arrange an array containing only 0s,1s and 2s, so that all 1s follow all 0s and all 2s follow 1s. e.g. 00000011111111222222. Linear time algorithm.


Input: {0,0,1,1,2,2,0,0,2,0,1,1,1,0,1};
Output: (0 0 0 0 0 0 1 1 1 1 1 2 2 2 }