荷兰国旗-三色查找

[0,1,1,0,2,2],6

返回：[0,0,1,1,2,2]

具体解法和三分切向快速排序很像[code]public class ThreeColor {
public static int[] sortThreeColor(int[] A, int n) {
int i=0,j=n-1;
for (int k = 0; k < n; k++) {
if (k>j)break;
if(A[k]==0) exch(A,k,i++);
if (A[k]==2)exch(A,k--,j--);
}
return A;
}
private static void exch(int[] a,int i,int j){
int t=a[i];
a[i]=a[j];
a[j]=t;
}
private static void show(int[] a){
for (int i = 0; i <a.length ; i++) {
System.out.print(a[i] + " ");
}
System.out.println();
}
public static void main(String[] args) {
int[] A=new int[]{1,2,0,2};
sortThreeColor(A,4);
show(A);
}
}