获取无重复字符的最长子串

  1     /**
  2      * 获取无重复字符的最长子串
  3      * @param srcStr
  4      * @return
  5      */
  6     public static String getMaxLenNoRepeatChar(String srcStr){
  7         if (srcStr==null){
  8             return null;
  9         }
 10         if (srcStr.isEmpty()){
 11             return null;
 12         }
 13 
 14         Random random = new Random();
 15         int count=0;
 16         HashSet<String> stringHashSet = new HashSet<>();
 17         while (true){
 18 
 19             int subStrBegIndex = random.nextInt(srcStr.length());
 20             int subStrEndIndex = random.nextInt(srcStr.length());
 21             int subStrEndIndex1 = subStrEndIndex + 1;
 22             if (subStrBegIndex<subStrEndIndex1){
 23                 String substring = srcStr.substring(subStrBegIndex, subStrEndIndex1);
 24                 stringHashSet.add(substring);
 25             }
 26             if (count>1000000){
 27                 break;
 28             }
 29             count++;
 30         }
 31 
 32         ArrayList<String> stringArrayList = new ArrayList<>();
 33         for (String s : stringHashSet) {
 34             boolean b = checkStrHasRepeatChar(s);
 35             if (!b){
 36                 stringArrayList.add(s);
 37             }
 38         }
 39 
 40         Collections.sort(stringArrayList, new Comparator<String>() {
 41             @Override
 42             public int compare(String o1, String o2) {
 43                 return o1.length()-o2.length();
 44             }
 45         });
 46 
 47         System.out.println(stringArrayList);
 48 
 49         HashMap<String, Integer> stringIntegerHashMap = new HashMap<>();
 50         for (String s : stringArrayList) {
 51             if (stringIntegerHashMap.containsKey(s.length()+"")){
 52                 stringIntegerHashMap.put(s.length()+"",stringIntegerHashMap.get(s.length()+"")+1);
 53             }else {
 54                 stringIntegerHashMap.put(s.length()+"",1);
 55             }
 56         }
 57 
 58         System.out.println(stringIntegerHashMap);
 59 
 60         ArrayList<CustmerStrCompute> custmerStrComputes = new ArrayList<>();
 61         for (Map.Entry<String,Integer> entry : stringIntegerHashMap.entrySet()){
 62             String key = entry.getKey();
 63             Integer value = entry.getValue();
 64 
 65             CustmerStrCompute custmerStrCompute = new CustmerStrCompute();
 66             custmerStrCompute.setId(UUID.randomUUID().toString());
 67             custmerStrCompute.setStrLen(Integer.valueOf(key));
 68             custmerStrCompute.setStrRepeatFrequence(value);
 69 
 70             custmerStrComputes.add(custmerStrCompute);
 71         }
 72 
 73         Collections.sort(custmerStrComputes, new Comparator<CustmerStrCompute>() {
 74             @Override
 75             public int compare(CustmerStrCompute o1, CustmerStrCompute o2) {
 76                 return o1.getStrLen()-o2.getStrLen();
 77             }
 78         });
 79 
 80         System.out.println(custmerStrComputes);
 81 
 82         CustmerStrCompute custmerStrCompute = custmerStrComputes.get(custmerStrComputes.size() - 1);
 83         Integer strLen = custmerStrCompute.getStrLen();
 84 //        Integer strRepeatFrequence = custmerStrCompute.getStrRepeatFrequence();
 85         ArrayList<String> stringArrayList1 = new ArrayList<>();
 86         for (String s : stringArrayList) {
 87             if (s.length()==strLen){
 88                 stringArrayList1.add(s);
 89             }
 90         }
 91         return stringArrayList1.toString();
 92     }
 93 
 94     /**
 95      * 判断字符串是否有重复字符
 96      * @param srcStr
 97      * @return
 98      */
 99     public static boolean checkStrHasRepeatChar(String srcStr){
100         if (srcStr==null){
101             return false;
102         }
103         if (srcStr.isEmpty()){
104             return false;
105         }
106 
107         HashMap<Character, Integer> characterIntegerHashMap = new HashMap<>();
108         for (int i = 0; i < srcStr.length(); i++) {
109             char c = srcStr.charAt(i);
110             if (characterIntegerHashMap.containsKey(c)){
111                 characterIntegerHashMap.put(c,characterIntegerHashMap.get(c)+1);
112             }else {
113                 characterIntegerHashMap.put(c,1);
114             }
115         }
116 
117         for (Map.Entry<Character,Integer> entry : characterIntegerHashMap.entrySet()){
118 //            Character key = entry.getKey();
119             Integer value = entry.getValue();
120 
121             if (value>=2){
122                 return true;
123             }
124         }
125         return false;
126     }
127 
128 class CustmerStrCompute{
129     private String id;
130     private Integer strLen;
131     private Integer strRepeatFrequence;
132 
133     public String getId() {
134         return id;
135     }
136 
137     public void setId(String id) {
138         this.id = id;
139     }
140 
141     public Integer getStrLen() {
142         return strLen;
143     }
144 
145     public void setStrLen(Integer strLen) {
146         this.strLen = strLen;
147     }
148 
149     public Integer getStrRepeatFrequence() {
150         return strRepeatFrequence;
151     }
152 
153     public void setStrRepeatFrequence(Integer strRepeatFrequence) {
154         this.strRepeatFrequence = strRepeatFrequence;
155     }
156 
157     @Override
158     public String toString() {
159         return "CustmerStrCompute{" +
160                 "id='" + id + '\'' +
161                 ", strLen=" + strLen +
162                 ", strRepeatFrequence=" + strRepeatFrequence +
163                 '}';
164     }
165 }