All anagrams

Author: ratulb

codes/all_anagrams.mojo

@@ -0,0 +1,76 @@
+### Find All Anagrams in a String
+### Return all start indices of anagrams of string p in string s.
+
+from collections import Dict
+
+
+fn find_anagrams(s: String, p: String) -> List[Int]:
+    if len(s) < len(p):
+        return List[Int]()
+    pdict = Dict[String, Int]()
+    sdict = Dict[String, Int]()
+    for i in range(len(p)):
+        pdict[p[i]] = 1 + pdict.get(p[i], 0)
+        sdict[s[i]] = 1 + sdict.get(s[i], 0)
+    result = List(0) if equals(pdict, sdict) else List[Int]()
+    left, right = 0, len(p)
+    while right < len(s):
+        sdict[s[right]] = 1 + sdict.get(s[right], 0)
+        sdict[s[left]] = sdict.get(s[left], 1) - 1
+        if sdict.get(s[left]) and sdict.get(s[left]).value() == 0:
+            try:
+                _ = sdict.pop(s[left])
+            except e:
+                print(e)
+        right += 1
+        left += 1
+        if equals(pdict, sdict):
+            result.append(left)
+    return result
+
+
+fn equals(read d1: Dict[String, Int], read d2: Dict[String, Int]) -> Bool:
+    if len(d1) != len(d2):
+        return False
+    for each in d1.items():
+        try:
+            if each[].value != d2[each[].key]:
+                return False
+        except e:
+            return False
+    return True
+
+
+from testing import assert_equal
+
+
+fn main() raises:
+    var s: String = "abc"
+    var p: String = "abc"
+    result = find_anagrams(s, p)
+    assert_equal(result, List(0), "Assertion failed")
+
+    s = "cba"
+    p = "abc"
+    result = find_anagrams(s, p)
+    assert_equal(result, List(0), "Assertion failed")
+
+    s = "cbaa"
+    p = "abc"
+    result = find_anagrams(s, p)
+    assert_equal(result, List(0), "Assertion failed")
+
+    s = "cbaacb"
+    p = "abc"
+    result = find_anagrams(s, p)
+    assert_equal(result, List(0, 3), "Assertion failed")
+
+    s = "cbaebabacd"
+    p = "abc"
+    result = find_anagrams(s, p)
+    assert_equal(result, List(0, 6), "Assertion failed")
+
+    s = "abab"
+    p = "ab"
+    result = find_anagrams(s, p)
+    assert_equal(result, List(0, 1, 2), "Assertion failed")

docs/all_anagrams.md

@@ -0,0 +1,83 @@
+### Find All Anagrams in a String
+### Return all start indices of anagrams of string p in string s.
+
+```python
+
+from collections import Dict
+
+
+fn find_anagrams(s: String, p: String) -> List[Int]:
+    if len(s) < len(p):
+        return List[Int]()
+    pdict = Dict[String, Int]()
+    sdict = Dict[String, Int]()
+    for i in range(len(p)):
+        pdict[p[i]] = 1 + pdict.get(p[i], 0)
+        sdict[s[i]] = 1 + sdict.get(s[i], 0)
+    result = List(0) if equals(pdict, sdict) else List[Int]()
+    left, right = 0, len(p)
+    while right < len(s):
+        sdict[s[right]] = 1 + sdict.get(s[right], 0)
+        sdict[s[left]] = sdict.get(s[left], 1) - 1
+        if sdict.get(s[left]) and sdict.get(s[left]).value() == 0:
+            try:
+                _ = sdict.pop(s[left])
+            except e:
+                print(e)
+        right += 1
+        left += 1
+        if equals(pdict, sdict):
+            result.append(left)
+    return result
+
+
+fn equals(read d1: Dict[String, Int], read d2: Dict[String, Int]) -> Bool:
+    if len(d1) != len(d2):
+        return False
+    for each in d1.items():
+        try:
+            if each[].value != d2[each[].key]:
+                return False
+        except e:
+            return False
+    return True
+
+
+from testing import assert_equal
+
+
+fn main() raises:
+    var s: String = "abc"
+    var p: String = "abc"
+    result = find_anagrams(s, p)
+    assert_equal(result, List(0), "Assertion failed")
+
+    s = "cba"
+    p = "abc"
+    result = find_anagrams(s, p)
+    assert_equal(result, List(0), "Assertion failed")
+
+    s = "cbaa"
+    p = "abc"
+    result = find_anagrams(s, p)
+    assert_equal(result, List(0), "Assertion failed")
+
+    s = "cbaacb"
+    p = "abc"
+    result = find_anagrams(s, p)
+    assert_equal(result, List(0, 3), "Assertion failed")
+
+    s = "cbaebabacd"
+    p = "abc"
+    result = find_anagrams(s, p)
+    assert_equal(result, List(0, 6), "Assertion failed")
+
+    s = "abab"
+    p = "ab"
+    result = find_anagrams(s, p)
+    assert_equal(result, List(0, 1, 2), "Assertion failed")
+
+```
+
+
+[Source](https://github.com/ratulb/mojo_programming/blob/main/codes/all_anagrams.mojo)

docs/index.md

@@ -63,4 +63,6 @@
 
 🟢 [Last word length](last_word_length.md) ➔ Return the length of the last word in a given space-separated string
 
-🟢 [Largest Number](largest_number.md) ➔ Arrange non-negative integers to form the largest possible number and return it as a string.
+🟢 [Largest Number](largest_number.md) ➔ Arrange non-negative integers to form the largest possible number and return it as a string.
+
+🟢 [Find All Anagrams in a String](all_anagrams.md) ➔ Return all start indices of anagrams of string p in string s.