荷兰国旗问题

 1 /***************************************
 2 FileName HollandFlag.cpp
 3 Author : godfrey
 4 CreatedTime : 2016/5/4
 5 ****************************************/
 6 #include <iostream>
 7 #include <cstring>
 8 #include <vector>
 9 #include <algorithm>
10 #include <stdio.h>
11 #include <stdlib.h>
12 
13 using namespace std;
14 
15 void HollandFlag(int* A,int size){
16     int begin = 0;
17     int end = size - 1;
18     int cur = 0;
19     while(cur <= end){
20         if(A[cur] == 2){
21             swap(A[cur],A[end]);
22             end --;
23         }
24         else if(A[cur] == 1){
25             cur ++;
26         }
27         else if(A[cur] == 0){
28             swap(A[cur],A[begin]);//这里简化了步骤，提醒：cur与begin是否相同，分情况考虑
29             begin ++;
30             cur ++;
31         }
32     }
33 }
34 int main()
35 {
36     int a[] = {0,1,2,0,0,2,1,2,1,2,2,1,1,0};
37     int size = sizeof(a)/sizeof(int);
38     for(int i=0;i<size;i++){
39         cout<<a[i]<<" ";
40     }
41     cout<<endl;
42     HollandFlag(a,size);
43     cout<<"-----------After adjusting ------------"<<endl;
44     for(int i=0;i<size;i++){
45         cout<<a[i]<<" ";
46     }
47     cout<<endl;
48     return 0;
49 }