N！的全排列算法(Java实现)

public class TestSort {

String[] list;

StringBuffer sb;

int len, start;

TestSort(String in) {

len = Integer.parseInt(in);

list = new String[len];

for (int i = 0; i < len; i++) list[i] = String.valueOf(i + 1);

permutation(0,len-1);

}

void swap(int c1, int c2) {

String temp = list[c1];

list[c1] = list[c2];

list[c2] = temp;

}

void permutation(int m,int n) {

if (m==n) {

sb = new StringBuffer();

for (int i = 0; i < len; i++) sb.append(list[i]);

sb.append(" ");

System.out.print(sb);

} else {

for (int i = m; i<=n; i++) {

swap(m, i);//交换

permutation(m+1,n);

swap(m,i);//还原

}

}

}

public static void main(String args[]) {

new TestSort("3");

}

}