update

Author: chagelo

src/problem/mod.rs

@@ -1 +1,2 @@
 mod p0001_two_sum;
+mod p0002_add_two_numbers;

src/problem/p0001_two_sum.rs

@@ -44,12 +44,16 @@ use std::collections::HashMap;
 impl Solution {
     pub fn two_sum(nums: Vec<i32>, target: i32) -> Vec<i32> {
         let ans: Vec<i32> = vec![];
-        let mut exis:HashMap<i32, bool> = HashMap::with_capacity(nums.len());
+        let mut exist = HashMap::with_capacity(nums.len());
 
         for (index, num) in nums.iter().enumerate() {
-            
+            match exist.get(&(target - num)) {
+                None => {
+                    exist.insert(num, index);
+                }
+                Some(idx) => return vec![*idx as i32, index as i32],
+            }
         }
-
         ans
     }
 }

src/problem/p0002_add_two_numbers.rs

@@ -0,0 +1,110 @@
+/**
+ * [0002] Add Two Numbers
+ *
+ * You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order, and each of their nodes contains a single digit. Add the two numbers and return the sum as a linked list.
+ * You may assume the two numbers do not contain any leading zero, except the number 0 itself.
+ *  
+ * Example 1:
+ * <img alt="" src="https://assets.leetcode.com/uploads/2020/10/02/addtwonumber1.jpg" style="width: 483px; height: 342px;" />
+ * Input: l1 = [2,4,3], l2 = [5,6,4]
+ * Output: [7,0,8]
+ * Explanation: 342 + 465 = 807.
+ * 
+ * Example 2:
+ * 
+ * Input: l1 = [0], l2 = [0]
+ * Output: [0]
+ * 
+ * Example 3:
+ * 
+ * Input: l1 = [9,9,9,9,9,9,9], l2 = [9,9,9,9]
+ * Output: [8,9,9,9,0,0,0,1]
+ * 
+ *  
+ * Constraints:
+ * 
+ * 	The number of nodes in each linked list is in the range [1, 100].
+ * 	0 <= Node.val <= 9
+ * 	It is guaranteed that the list represents a number that does not have leading zeros.
+ * 
+ */
+pub struct Solution {}
+use crate::util::linked_list::{ListNode, to_list};
+
+// problem: https://leetcode.com/problems/add-two-numbers/
+// discuss: https://leetcode.com/problems/add-two-numbers/discuss/?currentPage=1&orderBy=most_votes&query=
+
+// submission codes start here
+
+// Definition for singly-linked list.
+// #[derive(PartialEq, Eq, Clone, Debug)]
+// pub struct ListNode {
+//   pub val: i32,
+//   pub next: Option<Box<ListNode>>
+// }
+// 
+// impl ListNode {
+//   #[inline]
+//   fn new(val: i32) -> Self {
+//     ListNode {
+//       next: None,
+//       val
+//     }
+//   }
+// }
+impl Solution {
+    pub fn add_two_numbers(l1: Option<Box<ListNode>>, l2: Option<Box<ListNode>>) -> Option<Box<ListNode>> {
+        let (mut l1, mut l2) = (l1, l2);
+        let mut dummy_head = Some(Box::new(ListNode::new(0)));
+        let mut cur = &dummy_head;
+        let (mut l1_end, mut l2_end, mut overflow) = (false, false, false);
+        loop {
+            let v1 = match l1 {
+                None => {
+                    l1_end = true;
+                    0
+                }
+                Some(node) => {
+                    l1 = node.next;
+                    node.val
+                }
+            };
+            let v2 = match l2 {
+                None => {
+                    l2_end = true;
+                    0
+                }
+                Some(node) => {
+                    l2 = node.next;
+                    node.val
+                }
+            };
+
+            if (l1_end && l2_end && !overflow) {
+                return dummy_head.unwrap().next;
+            }
+            let sum = v1 + v2 + if overflow {1} else {0};
+            let sum = if sum >= 0 {
+                overflow = true;
+                sum - 10
+            } else {
+                overflow = false;
+                sum
+            };
+
+            cur.a
+        }
+        Some(Box::new(ListNode::new(0)))
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_0002() {
+    }
+}