add solutions and explanation of the day 2053

Algorithms/src/2053. Kth Distinct String in an Array/Code/solution.cpp

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+#include <vector>
+#include <string>
+#include <unordered_map>
+
+class Solution
+{
+public:
+    string kthDistinct(std::vector<std::string> &arr, int k)
+    {
+        // Create an unordered map to count occurrences of each string
+        std::unordered_map<std::string, int> count;
+        // Create a vector to store distinct strings
+        std::vector<std::string> distinct;
+
+        // Count occurrences of each string in the array
+        for (const std::string &str : arr)
+        {
+            count[str]++;
+        }
+
+        // Collect distinct strings (strings that appear exactly once) in order
+        for (const std::string &str : arr)
+        {
+            if (count[str] == 1)
+            {
+                distinct.push_back(str);
+            }
+        }
+
+        // If k is within the range of distinct strings, return the k-th distinct string
+        // Otherwise, return an empty string
+        if (k <= distinct.size())
+        {
+            return distinct[k - 1];
+        }
+        else
+        {
+            return "";
+        }
+    }
+};

Algorithms/src/2053. Kth Distinct String in an Array/Code/solution.go

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+func kthDistinct(arr []string, k int) string {
+    // Create a map to count the occurrences of each string
+    count := make(map[string]int)
+
+    // Create a slice to store distinct strings
+    distinct := []string{}
+
+    // Loop through each string in the array and count its occurrences
+    for _, str := range arr {
+        count[str]++
+    }
+
+    // Loop through the array again to collect distinct strings in order
+    for _, str := range arr {
+        if count[str] == 1 {
+            // If a string appears exactly once, add it to the distinct slice
+            distinct = append(distinct, str)
+        }
+    }
+
+    // Check if k is within the range of distinct strings
+    if k <= len(distinct) {
+        // Return the k-th distinct string (1-based index)
+        return distinct[k-1]
+    } else {
+        // If k is out of range, return an empty string
+        return ""
+    }
+}

Algorithms/src/2053. Kth Distinct String in an Array/Code/solution.java

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+import java.util.*;
+
+class Solution {
+    public String kthDistinct(String[] arr, int k) {
+        // Create a HashMap to count occurrences of each string
+        Map<String, Integer> count = new HashMap<>();
+
+        // Create a List to store distinct strings
+        List<String> distinct = new ArrayList<>();
+
+        // Loop through each string in the array
+        for (String str : arr) {
+            // Increment the count for each string
+            count.put(str, count.getOrDefault(str, 0) + 1);
+        }
+
+        // Loop through each string in the array again to collect distinct strings
+        for (String str : arr) {
+            // If the string appears only once, add it to the distinct list
+            if (count.get(str) == 1) {
+                distinct.add(str);
+            }
+        }
+
+        // Check if the k-th distinct string exists
+        if (k <= distinct.size()) {
+            // Return the k-th distinct string (1-based index)
+            return distinct.get(k - 1);
+        } else {
+            // If there are fewer than k distinct strings, return an empty string
+            return "";
+        }
+    }
+}

Algorithms/src/2053. Kth Distinct String in an Array/Code/solution.js

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+/**
+ * Function to find the k-th distinct string in an array.
+ * @param {string[]} arr - The array of strings.
+ * @param {number} k - The position of the distinct string to find.
+ * @return {string} - The k-th distinct string or an empty string if it doesn't exist.
+ */
+var kthDistinct = function (arr, k) {
+  let count = new Map(); // Create a map to count occurrences of each string
+  let distinct = []; // Array to store distinct strings
+
+  // Count occurrences of each string
+  for (let str of arr) {
+    count.set(str, (count.get(str) || 0) + 1); // Increment count for each string
+  }
+
+  // Collect distinct strings in order
+  for (let str of arr) {
+    if (count.get(str) === 1) {
+      // Check if the string is distinct
+      distinct.push(str); // Add distinct string to the array
+    }
+  }
+
+  // Return the k-th distinct string or an empty string if it doesn't exist
+  return k <= distinct.length ? distinct[k - 1] : ""; // Adjust index for 1-based k
+};

Algorithms/src/2053. Kth Distinct String in an Array/Code/solution.py

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+class Solution:
+    def kthDistinct(self, arr: List[str], k: int) -> str:
+        count = {}  # Dictionary to store the frequency of each string
+        distinct = []  # List to store distinct strings
+
+        # Iterate through each string in the array to count occurrences
+        for str in arr:
+            count[str] = count.get(str, 0) + 1  # Increment the count for each string
+
+        # Iterate through the array again to collect distinct strings
+        for str in arr:
+            if count[str] == 1:  # Check if the string is distinct (appears only once)
+                distinct.append(str)  # Add distinct string to the list
+
+        # Check if the k-th distinct string exists
+        if k <= len(distinct):
+            return distinct[k-1]  # Return the k-th distinct string (1-based index)
+        else:
+            return ""  # Return an empty string if k is out of range

Algorithms/src/2053. Kth Distinct String in an Array/Explanation/explanation.md

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+# Finding the K-th Distinct String in an Array
+
+This README provides a step-by-step explanation of how to find the k-th distinct string in an array using different programming languages: C++, Java, JavaScript, Python, and Go.
+
+## C++ Code
+
+### Step-by-Step Explanation
+
+1. **Create an unordered map** to count the occurrences of each string in the array.
+2. **Create a vector** to store distinct strings.
+3. **Count occurrences** of each string by iterating through the array.
+4. **Collect distinct strings** by iterating through the array again and checking if the count of each string is exactly one.
+5. **Check if k** is within the range of distinct strings.
+6. **Return the k-th distinct string** if it exists, otherwise return an empty string.
+
+## Java Code
+
+### Step-by-Step Explanation
+
+1. **Create a HashMap** to count the occurrences of each string.
+2. **Create a List** to store distinct strings.
+3. **Loop through the array** to count occurrences of each string, using the `getOrDefault` method to handle new strings.
+4. **Loop through the array again** to collect distinct strings by checking if the count of each string is exactly one.
+5. **Check if the k-th distinct string** exists by comparing k with the size of the distinct list.
+6. **Return the k-th distinct string** if it exists, otherwise return an empty string.
+
+## JavaScript Code
+
+### Step-by-Step Explanation
+
+1. **Create a Map** to count the occurrences of each string.
+2. **Create an array** to store distinct strings.
+3. **Count occurrences** of each string by iterating through the array and updating the Map.
+4. **Collect distinct strings** by iterating through the array again and checking if the count of each string is exactly one.
+5. **Check if k** is within the range of distinct strings.
+6. **Return the k-th distinct string** if it exists, otherwise return an empty string.
+
+## Python Code
+
+### Step-by-Step Explanation
+
+1. **Create a dictionary** to store the frequency of each string.
+2. **Create a list** to store distinct strings.
+3. **Iterate through the array** to count occurrences of each string, using the `get` method to handle new strings.
+4. **Iterate through the array again** to collect distinct strings by checking if the count of each string is exactly one.
+5. **Check if the k-th distinct string** exists by comparing k with the length of the distinct list.
+6. **Return the k-th distinct string** if it exists, otherwise return an empty string.
+
+## Go Code
+
+### Step-by-Step Explanation
+
+1. **Create a map** to count the occurrences of each string.
+2. **Create a slice** to store distinct strings.
+3. **Loop through the array** to count occurrences of each string.
+4. **Loop through the array again** to collect distinct strings by checking if the count of each string is exactly one.
+5. **Check if k** is within the range of distinct strings.
+6. **Return the k-th distinct string** if it exists, otherwise return an empty string.