Hashing

Classes/module 6/12 - hasing3/Quesiton/Longest subarr/Solution.java

@@ -0,0 +1,22 @@
+public class Solution {
+    public int solve(int[] A) {
+        HashMap<Long, Integer> sumMap = new HashMap<>();
+        long cumSum =0;
+        int maxLength =0;
+
+        for (int i = 0; i < A.length; i++) {
+            cumSum += A[i];
+
+            if(cumSum == 0){
+                maxLength = i + 1;
+            } else if(sumMap.containsKey(cumSum)){
+                 int length = i - sumMap.get(cumSum);
+                maxLength = Math.max(maxLength, length);
+            } else {
+                sumMap.put(cumSum, i);
+            }
+        }
+
+        return maxLength;
+    }
+}

Classes/module 6/12 - hasing3/Quesiton/shaggy/Solution.java

@@ -0,0 +1,16 @@
+public class Solution {
+    public int solve(int[] A) {
+        HashMap<Integer, Integer> lastIndexMap = new HashMap<>();
+        int minDistance = Integer.MAX_VALUE;
+
+        for (int i = 0; i < A.length; i++) {
+            if (lastIndexMap.containsKey(A[i])) {
+                int distance = i - lastIndexMap.get(A[i]);
+                minDistance = Math.min(minDistance, distance);
+            }
+            lastIndexMap.put(A[i], i);
+        }
+
+        return minDistance == Integer.MAX_VALUE ? -1 : minDistance;
+    }
+}