java算法之字符組合排序

Java字符組合排序，不是特別難的題目，暴力算和用圖論算（深度遍歷）都可以，結果是198.圖論的話就是構造無向圖，然後深度優先遞歸。
題目:用1、2、2、3、4、5這六個數字，用Java寫一個main函數，打印出所有不同的排列，如：512234、412345等，要求："4"不能在第三位，"3"與"5"不能相連。

Java代碼：

package com.graphic;  
import Java.util.Iterator;  
import Java.util.TreeSet;  
public class CharSequence {  
private String[] c = {"1","2","2","3","4","5"};  
private int n = c.length;  
private boolean[] visited = new boolean[n];  
private int[][] g = new int[n][n];  
private TreeSet ts = new TreeSet();  
private String result = "";  
public CharSequence(){  
for(int i=0; i  
for(int j=0; j  
if(i == j) g[i][j] = 0;  
else g[i][j] = 1;  
}  
}  
g[3][5] = 0;  
g[5][3] = 0;  
}  
public void depthFirst(int index){  
visited[index] = true;  
result += c[index];  
if(result.length() == n){  
ts.add(result);  
resultresult = result.substring(0,result.length()-1);  
visited[index] = false;  
}  
else{  
for(int i=0; i  
if(!visited[i] && g[index][i] == 1){  
depthFirst(i);  
}else continue;  
}  
resultresult = result.substring(0,result.length()-1);  
visited[index] = false;  
}  
}  
public void graphicGet(){  
for(int i=0; i  
depthFirst(i);  
}  
int count = 0;  
System.out.print("圖論的結果：");  
Iterator it = ts.iterator();  
while(it.hasNext()){  
String tmp = it.next();  
if(tmp.contains("35")) continue;  
if(tmp.contains("53")) continue;  
if(tmp.charAt(3) == '4') continue;  
System.out.println(tmp);  
count++;  
}  
System.out.println("共計："+count+"個");  
}  
public void bruteForce(){  
System.out.println("暴力搜的結果：");  
int count = 0;  
for(int i = 122345; i<543222; i++){  
String tmp = ""+i;  
if(tmp.charAt(3) == '4') continue;  
if(tmp.contains("35")) continue;  
if(tmp.contains("53")) continue;  
if(tmp.contains("5") && tmp.contains("4") && tmp.contains("3") && tmp.contains("1"))  
{  
int index = tmp.indexOf("2");  
if(index == -1) continue;  
if(index == tmp.length()-1) continue;  
if(tmp.substring(index+1).contains("2")){  
System.out.println(tmp);  
count++;  
}  
}  
}  
System.out.print("共計："+count+"個");  
}  
public void recrusive(){  
}  
public static void main(String[] args) {  
CharSequence cs = new CharSequence();  
//圖論的方法  
cs.graphicGet();  
//暴力搜索  
cs.bruteForce();  
}  
} 

通過例子，希望會對你有幫助。下面一篇將要介紹Java排序算法總結。