Efficient java version of permutation and combination algorithm

This article is an example of java permutation and combination algorithm to share the specific code, for your reference, the specific content is as follows

package BeanUtil;
import java.util.ArrayList;
import java.util.List;
import com.work.core.exception.OurException;
/**
 *  Statistics of 3 The combination of the most probable occurrences 
 * 
 * @author wangmingjie
 * @date 2009-1-1 In the afternoon 01:22:19
 */
public class Copy_2_of_StatisAnyThree {
//  Combination algorithm   
//   The idea of this procedure is to open 1 Is an array whose subscripts denote 1 to m The number of elements in the array 1 That's its subscript   
//   The number represented is selected 0 It's not selected.    
//   First initialize, put the array before n An element set 1 , said the first 1 The combination is the front n Number.    
//   Then scan the array element values from left to right. 10 "Combination, find the first 1 A" 10 "And then change it to   
//   " 01 "Combine it all to the left at the same time." 1 "Move everything to the leftmost end of the array.    
//   When the first 1 A" 1 "Moves to the array m-n Is, i.e n A" 1 "When you move everything to the far right, you have to   
//   At the end of the day 1 A combination.    
//   For example, o 5 select 3 A combination of:    
//  1  1  1  0  0  //1,2,3   
//  1  1  0  1  0  //1,2,4   
//  1  0  1  1  0  //1,3,4   
//  0  1  1  1  0  //2,3,4   
//  1  1  0  0  1  //1,2,5   
//  1  0  1  0  1  //1,3,5   
//  0  1  1  0  1  //2,3,5   
//  1  0  0  1  1  //1,4,5   
//  0  1  0  1  1  //2,4,5   
//  0  0  1  1  1  //3,4,5  
  public static void main(String[] args) {
    Copy_2_of_StatisAnyThree s = new Copy_2_of_StatisAnyThree();
    s.printAnyThree();   
  }
  
  /**
   * 
   */
  public void printAnyThree(){
    int[] num = new int[]{1,2,3,4,5,6};
    print(combine(num,3));
  }
  /**
   *  from n Choose from two numbers m A digital 
   * @param a
   * @param m
   * @return
   */
  public List combine(int[] a,int m){
    int n = a.length;
    if(m>n){
      throw new OurException(" Error! An array of a Only in the "+n+" An element. "+m+" Is greater than "+2+"!!!");
    }
    
    List result = new ArrayList();
    
    int[] bs = new int[n];
    for(int i=0;i<n;i++){
      bs[i]=0;
    }
    // Initialize the 
    for(int i=0;i<m;i++){
      bs[i]=1;
    }
    boolean flag = true;
    boolean tempFlag = false;
    int pos = 0;
    int sum = 0;
    // So let's go to the first 1 a 10 Combine it, and then it becomes 01 And I'm going to take all of the left-hand side 1 Move to the leftmost part of the array 
    do{
      sum = 0;
      pos = 0;
      tempFlag = true; 
      result.add(print(bs,a,m));
      
      for(int i=0;i<n-1;i++){
        if(bs[i]==1 && bs[i+1]==0 ){
          bs[i]=0;
          bs[i+1]=1;
          pos = i;
          break;
        }
      }
      // To the left of the 1 Move everything to the leftmost part of the array 
      
      for(int i=0;i<pos;i++){
        if(bs[i]==1){
          sum++;
        }
      }
      for(int i=0;i<pos;i++){
        if(i<sum){
          bs[i]=1;
        }else{
          bs[i]=0;
        }
      }
      
      // Check if all 1 They've all moved to the far right 
      for(int i= n-m;i<n;i++){
        if(bs[i]==0){
          tempFlag = false;
          break;
        }
      }
      if(tempFlag==false){
        flag = true;
      }else{
        flag = false;
      }
      
    }while(flag);
    result.add(print(bs,a,m));
    
    return result;
  }
  
  private int[] print(int[] bs,int[] a,int m){
    int[] result = new int[m];
    int pos= 0;
    for(int i=0;i<bs.length;i++){
      if(bs[i]==1){
        result[pos]=a[i];
        pos++;
      }
    }
    return result ;
  }
  
  private void print(List l){
    for(int i=0;i<l.size();i++){
      int[] a = (int[])l.get(i);
      for(int j=0;j<a.length;j++){
        System.out.print(a[j]+"/t");
      }
      System.out.println();
    }
  }
}