Merge pull request #1 from Madhu2244/patch-1

Create LongestSubstringKDistinct.java

Author: ishaanjav

LongestSubstringKDistinct.java

@@ -0,0 +1,34 @@
+import java.util.HashMap;
+import java.util.Map;
+
+public class LongestSubstringKDistinct 
+{
+	
+	public static void main(String[] args) 
+	{
+		//input
+		String str = "AAAHHIBC";
+		int k = 2;
+		
+		int windowStart = 0; 
+		int maxLength = 0;
+		Map<Character, Integer> charFreqMap = new HashMap<>();
+		for (int windowEnd = 0; windowEnd < str.length(); windowEnd++){
+			char rightChar = str.charAt(windowEnd);
+			charFreqMap.put(rightChar, charFreqMap.getOrDefault(rightChar, 0) + 1);
+			while (charFreqMap.size() > k) {
+				char leftChar = str.charAt(windowStart);
+				charFreqMap.put(leftChar, charFreqMap.get(leftChar) - 1);
+				if (charFreqMap.get(leftChar) == 0)
+				{
+					charFreqMap.remove(leftChar);
+				}
+				windowStart++;
+			}
+			maxLength = Math.max(maxLength, windowEnd - windowStart + 1);
+		}
+		System.out.println(maxLength);
+		
+	}
+
+}