diff --git a/src/problem/mod.rs b/src/problem/mod.rs
index 3d2663d..9b7bec2 100644
--- a/src/problem/mod.rs
+++ b/src/problem/mod.rs
@@ -692,3 +692,5 @@ mod p2929_distribute_candies_among_children_ii;
 mod p1298_maximum_candies_you_can_get_from_boxes;
 
 mod p3403_find_the_lexicographically_largest_string_from_the_box_i;
+
+mod p1061_lexicographically_smallest_equivalent_string;
diff --git a/src/problem/p1061_lexicographically_smallest_equivalent_string.rs b/src/problem/p1061_lexicographically_smallest_equivalent_string.rs
new file mode 100644
index 0000000..fa2f685
--- /dev/null
+++ b/src/problem/p1061_lexicographically_smallest_equivalent_string.rs
@@ -0,0 +1,131 @@
+/**
+ * [1061] Lexicographically Smallest Equivalent String
+ */
+pub struct Solution {}
+
+// submission codes start here
+
+/// Use union find set for this question
+struct EquivalentSet {
+    parents: Vec<usize>,
+    min_values: Vec<usize>,
+}
+
+impl std::fmt::Debug for EquivalentSet {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "parents: \n")?;
+
+        for (i, &v) in self.parents.iter().enumerate() {
+            write!(
+                f,
+                "{} -> {}\n",
+                Self::convert_to_char(i),
+                Self::convert_to_char(v)
+            )?;
+        }
+
+        writeln!(f, "min_values:")?;
+
+        for (i, &v) in self.min_values.iter().enumerate() {
+            writeln!(
+                f,
+                "{} -> {}",
+                Self::convert_to_char(i),
+                Self::convert_to_char(v)
+            )?;
+        }
+
+        Ok(())
+    }
+}
+
+impl EquivalentSet {
+    fn new() -> Self {
+        Self {
+            // Only lower characters
+            parents: (0..26).collect(),
+            min_values: (0..26).collect(),
+        }
+    }
+
+    fn convert_to_char(c: usize) -> char {
+        (c as u8 + b'a') as char
+    }
+
+    fn find(&mut self, a: usize) -> (usize, usize) {
+        if self.parents[a] == a {
+            (a, self.min_values[a])
+        } else {
+            let (p, min_value) = self.find(self.parents[a]);
+            self.parents[a] = p;
+            self.min_values[a] = min_value;
+            (p, min_value)
+        }
+    }
+
+    fn merge(&mut self, a: usize, b: usize) {
+        let ((a_p, a_min_value), (b_p, b_min_value)) = (self.find(a), self.find(b));
+        let min_value = a_min_value.min(b_min_value).min(a).min(b);
+
+        self.parents[a_p] = b_p;
+        self.min_values[a_p] = min_value;
+        self.min_values[b_p] = min_value;
+    }
+}
+
+impl Solution {
+    pub fn smallest_equivalent_string(s1: String, s2: String, base_str: String) -> String {
+        let mut set = EquivalentSet::new();
+
+        for (a, b) in s1.bytes().zip(s2.bytes()) {
+            set.merge((a - b'a') as usize, (b - b'a') as usize);
+        }
+
+        String::from_utf8(
+            base_str
+                .bytes()
+                .map(|c| {
+                    let (_, min_value) = set.find((c - b'a') as usize);
+
+                    min_value as u8 + b'a'
+                })
+                .collect(),
+        )
+        .unwrap()
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_1061() {
+        assert_eq!(
+            "makkek",
+            Solution::smallest_equivalent_string(
+                "parker".to_string(),
+                "morris".to_string(),
+                "parser".to_string()
+            )
+        );
+        assert_eq!(
+            "hdld",
+            Solution::smallest_equivalent_string(
+                "hello".to_string(),
+                "world".to_string(),
+                "hold".to_string()
+            )
+        );
+        assert_eq!(
+            "aauaaaaada".to_string(),
+            Solution::smallest_equivalent_string(
+                "leetcode".to_string(),
+                "programs".to_string(),
+                "sourcecode".to_string()
+            )
+        );
+    }
+}