import org.junit.Test;
public class AllSort {
 public void permutation(char[] buf, int start, int end) {
  if (start == end) {// 当只要求对数组中一个字母进行全排列时，只要就按该数组输出即可
   for (int i = 0; i <= end; i++) {
    System.out.print(buf[i]);
   }
   System.out.println();
  } else {// 多个字母全排列
   for (int i = start; i <= end; i++) {
    char temp = buf[start];// 交换数组第一个元素与后续的元素
    buf[start] = buf[i];
    buf[i] = temp;
    permutation(buf, start + 1, end);// 后续元素递归全排列
    temp = buf[start];// 将交换后的数组还原
    buf[start] = buf[i];
    buf[i] = temp;
   }
  }
 }
 @Test
 public void testPermutation() throws Exception {
  char[] buf = new char[] { 'a', 'b', 'c' };
  permutation(buf, 0, 2);
 } 
}