Problem02 using ArrayList

java8/src/main/java/com/shekhargulati/leetcode/Problem01.java → java8/src/main/java/com/shekhargulati/leetcode/algorithms/Problem01.java

@@ -1,4 +1,4 @@
-package com.shekhargulati.leetcode;
+package com.shekhargulati.leetcode.algorithms;
 
 import java.util.Arrays;
 import java.util.HashMap;

java8/src/main/java/com/shekhargulati/leetcode/algorithms/Problem02.java

@@ -0,0 +1,60 @@
+package com.shekhargulati.leetcode.algorithms;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * You are given two linked lists representing two non-negative numbers.
+ * The digits are stored in reverse order and each of their nodes contain a single digit.
+ * Add the two numbers and return it as a linked list.
+ * <p>
+ * Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)
+ * Output: 7 -> 0 -> 8
+ */
+public class Problem02 {
+
+    public static void main(String[] args) {
+        /*
+        1. Iterate over two lists together
+        2. Add the two numbers at ith position
+        3. If numbers add upto greater than equal to 10 then store the remainder at current position and store 1 as next
+        4. When you are adding up next number add one
+         */
+
+        long start = System.currentTimeMillis();
+        List<Integer> first = Arrays.asList(2, 4, 3);
+        List<Integer> second = Arrays.asList(5, 6, 4);
+
+        List<Integer> result = new ArrayList<>();
+
+        int rem = 0;
+        for (int i = 0; i < first.size(); i++) {
+            int a = first.get(i);
+            int b = second.get(i);
+            int sum = a + b;
+            if (a + b >= 10) {
+                result.add(rem + sum % 10);
+                rem = 1;
+            } else {
+                result.add(rem + sum);
+                rem = 0;
+            }
+        }
+
+        System.out.println(result);
+        long end = System.currentTimeMillis();
+        System.out.println(String.format("Total time taken %d millis", (end - start)));
+
+    }
+
+    private class ListNode {
+        int val;
+        ListNode next;
+
+        public ListNode(int val) {
+            this.val = val;
+        }
+    }
+
+}

java8/src/test/java/com/shekhargulati/leetcode/Problem01Test.java

@@ -1,5 +1,6 @@
 package com.shekhargulati.leetcode;
 
+import com.shekhargulati.leetcode.algorithms.Problem01;
 import org.junit.Test;
 
 import java.util.Arrays;