Sorting algorithm 0-1, 0-1-2 sort

Before encountering a very interesting topic, is about the problem of sorting algorithm:

Known: An array: array element: 0 or 1 or 2

Solve: Sort the array by 0-1-2?

1Template <classT>2 voidSwap (t& t1, t&T2)3 {4T tmp =T1;5T1 =T2;6t2 =tmp;7 }8 9 //sorting a array which the elements is 0 or 1.Ten voidSortarray_0_1 (int* Arr,intN) One { A     intFirst =0;//Point to 0. -     intLast = n-1;//Point to 1. -  the      while(First <Last ) -     { -         //Find the position of first 0. -          while(0==Arr[first]) +         { -first++; +         } A  at         //Find The position of first 1. -          while(1==Arr[last]) -         { -last--; -         } -  in         if(First <= last &&1= = Arr[first] &&0==Arr[last]) -         { to Swap (Arr[first], arr[last]); +first++; -last--; the         } *     } $ }Panax Notoginseng  - //sorting a array which the elements is 0 or 1. the voidSortarray2_0_1 (int* Arr,intN) + { A     //int first = 0; //Point to 0. the     intLast = n-1;//Point to 2. +     intK =0;//Point to 1. -  $      while(K <Last ) $     { -         //Find 0. -         if(1==Arr[k]) the         { -              while(1= = Arr[last] && k <Last )Wuyi             { thelast--; -             } Wu  -             if(K <Last ) About             { $ Swap (Arr[k], arr[last]); -             } -         } -  A         if(0==Arr[k]) +         { thek++; -         } $     } the } the  the //sorting a array which the elements is 0 or 1 or 2. the voidSortarry_0_1_2 (int* Arr,intN) - { in     intFirst =0;//Point to 0. the     intLast = n-1;//Point to 2. the     intK =0;//Point to 1. About  the      while(K <Last ) the     { the         //Find 0. +         if(0==Arr[k]) -         { the              while(0= = Arr[first] && First <k)Bayi             { thefirst++; the             } -  -             if(First <k) the             { the Swap (Arr[k], Arr[first]); the             } the         } -  the         //Find 1. the         if(1= = Arr[k] | | K = =First ) the         {94k++; the         } the  the         //Find 2.98         if(2==Arr[k]) About         { -              while(2= = Arr[last] && k <Last )101             {102last--;103             }104  the             if(K <Last )106             {107 Swap (Arr[k], arr[last]);108             }109         } the     }111}

Sorting algorithm 0-1, 0-1-2 sort