Add 1061

Author: trung-hn

Readme.md

@@ -115,6 +115,7 @@
 | 1032 | Stream of Characters | Hard | O(M) | O(M) | Trie | | |
 | 1035 | Uncrossed Lines | Medium | O(N^2) | O(N) | Array, Dynamic Programming | | |
 | 1060 | Missing Element in Sorted Array | Medium | O(logN) | O(1) | Binary Search | | 🔒 |
+| 1061 | Lexicographically Smallest Equivalent String | Medium | O(N) | O(N) | DFS, Union Find | | 🔒 |
 | 1094 | Car Pooling | Medium | O(N) | O(1) | Car Pooling | | |
 | 1232 | Check If It Is a Straight Line | Easy | O(N) | O(1) | Math, Pythonic, Geometry | | |
 | 1277 | Count Square Submatrices with All Ones | Medium | O(N * M) | O(1) | Array, Dynamic Programming | | |

src/1061.py

@@ -0,0 +1,35 @@
+# TAGS: DFS, Union Find
+# REVIEWME: Union Find
+class Solution:
+    # 44 ms, 66.18%. Time and Space: O(N)
+    def smallestEquivalentString(self, A: str, B: str, S: str) -> str:
+        class UF:
+            def __init__(self):
+                self.array = list(range(26))
+
+            def union(self, parent, child):
+                parent = self.find(parent)
+                child = self.find(child)
+                if parent > child: 
+                    parent, child = child, parent
+                self.array[child] = parent
+
+            def find(self, value): # find and assign parent
+                if value != self.array[value]:
+                    parent = self.array[value]
+                    self.array[value] = self.find(parent)
+                return self.array[value]
+
+        disjoint_set = UF()
+        for c1, c2 in zip(A, B):
+            c1 = ord(c1) - ord('a')
+            c2 = ord(c2) - ord('a')
+            disjoint_set.union(c1, c2)
+
+        ans = []
+        for c in S:
+            index = ord(c) - ord('a')
+            parent = disjoint_set.find(index)
+            ans.append(chr(parent + ord('a')))
+
+        return "".join(ans)