solve problem Find All Anagrams In A String

Author: P-ppc

README.md

@@ -183,6 +183,7 @@ All solutions will be accepted!
 |459|[Repeated Substring Pattern](https://leetcode-cn.com/problems/repeated-substring-pattern/description/)|[java/py/js](./algorithms/RepeatedSubstringPattern)|Easy|
 |581|[Shortest Unsorted Continuous Subarray](https://leetcode-cn.com/problems/shortest-unsorted-continuous-subarray/description/)|[java/py/js](./algorithms/ShortestUnsortedContinuousSubarray)|Easy|
 |443|[String Compression](https://leetcode-cn.com/problems/string-compression/description/)|[java/py/js](./algorithms/StringCompression)|Easy|
+|438|[Find All Anagrams In A String](https://leetcode-cn.com/problems/find-all-anagrams-in-a-string/description/)|[java/py/js](./algorithms/FindAllAnagramsInAString)|Easy|
 
 # Database
 |#|Title|Solution|Difficulty|

algorithms/FindAllAnagramsInAString/README.md

@@ -0,0 +1,2 @@
+# Find All Anagrams In A String
+This problem is easy to solve by hashmap

algorithms/FindAllAnagramsInAString/Solution.java

@@ -0,0 +1,45 @@
+class Solution {
+    public List<Integer> findAnagrams(String s, String p) {
+        List<Integer> res = new ArrayList<Integer>();
+        Map<Character, Integer> patternMap = new HashMap<Character, Integer>();
+        int patternLength = p.length(),
+            beg = 0,
+            length = 0,
+            i = 0;
+        
+        for (char c : p.toCharArray()) {
+            Integer count;
+            if ((count = patternMap.get(c)) == null) patternMap.put(c, 1);
+            else patternMap.put(c, count + 1);
+        }
+        
+        Map<Character, Integer> copyPatternMap = new HashMap<Character, Integer>(patternMap);
+        
+        while (i < s.length()) {
+            Integer count;
+            if ((count = copyPatternMap.get(s.charAt(i))) == null) {
+                copyPatternMap = new HashMap<Character, Integer>(patternMap);
+                length = 0;
+                beg = ++i;
+            } else if (count > 0) {
+                copyPatternMap.put(s.charAt(i), count - 1);
+                length++;
+                i++;
+            } else {
+                while (s.charAt(beg++) != s.charAt(i)) {
+                    copyPatternMap.put(s.charAt(beg - 1), copyPatternMap.get(s.charAt(beg - 1)) + 1);
+                    length--;
+                }
+                i++;
+            }
+            
+            if (length == patternLength) {
+                res.add(beg);
+                copyPatternMap.put(s.charAt(beg), copyPatternMap.get(s.charAt(beg++)) + 1);
+                length--;
+            }
+        } 
+        
+        return res;
+    }
+}

algorithms/FindAllAnagramsInAString/solution.js

@@ -0,0 +1,50 @@
+/**
+ * @param {string} s
+ * @param {string} p
+ * @return {number[]}
+ */
+var findAnagrams = function(s, p) {
+    let res = [],
+        patternLength = p.length,
+        patternMap = {}
+        beg = 0,
+        length = 0,
+        i = 0
+    
+    for (let j = 0; j < patternLength; j++) {
+        if (patternMap[p[j]] === undefined) patternMap[p[j]] = 0
+        patternMap[p[j]] += 1
+    }
+    
+    let copyPatternMap = JSON.parse(JSON.stringify(patternMap))
+    
+    while (i < s.length) {
+        if (length < patternLength) {
+            if (copyPatternMap[s[i]] === undefined) {
+                copyPatternMap = JSON.parse(JSON.stringify(patternMap))
+                length = 0
+                i++
+                beg = i
+            } else if (copyPatternMap[s[i]] > 0) {
+                copyPatternMap[s[i]]--
+                length++
+                i++
+            } else {
+                while (s[beg++] !== s[i]) {
+                    copyPatternMap[s[beg - 1]]++
+                    length--
+                }
+                i++
+            }
+        }
+        
+        if (length === patternLength) {
+            res.push(beg)
+            copyPatternMap[s[beg]]++
+            length--
+            beg++
+        }
+    }
+    
+    return res
+};

algorithms/FindAllAnagramsInAString/solution.py

@@ -0,0 +1,47 @@
+class Solution(object):
+    def findAnagrams(self, s, p):
+        """
+        :type s: str
+        :type p: str
+        :rtype: List[int]
+        """
+        res = []
+        pattern_length = len(p)
+        pattern_map = {}
+        for c in p:
+            if pattern_map.get(c) == None:
+                pattern_map[c] = 0
+            pattern_map[c] += 1
+
+        copy_pattern_map = dict(pattern_map)
+        beg = 0
+        length = 0
+        i = 0
+        
+        while i < len(s):
+            if length < pattern_length:
+                if copy_pattern_map.get(s[i]) == None:
+                    copy_pattern_map = dict(pattern_map)
+                    length = 0
+                    i += 1
+                    beg = i
+                elif copy_pattern_map[s[i]] > 0:
+                    copy_pattern_map[s[i]] -= 1
+                    length += 1
+                    i += 1
+                else:
+                    while s[beg] != s[i]:
+                        copy_pattern_map[s[beg]] += 1
+                        length -= 1
+                        beg += 1
+                    # in this place s[beg] == s[i], so we have to go forward 1 distance
+                    beg += 1
+                    i += 1
+            
+            if length == pattern_length:
+                res.append(beg)
+                copy_pattern_map[s[beg]] += 1
+                length -= 1
+                beg += 1
+        
+        return res