day 2

Author: sachuverma

Leetcode Daily Challenge/March-2021/02. Set Mismatch.cpp

@@ -0,0 +1,43 @@
+/*
+Set Mismatch
+============
+
+You have a set of integers s, which originally contains all the numbers from 1 to n. Unfortunately, due to some error, one of the numbers in s got duplicated to another number in the set, which results in repetition of one number and loss of another number.
+
+You are given an integer array nums representing the data status of this set after the error.
+
+Find the number that occurs twice and the number that is missing and return them in the form of an array.
+
+Example 1:
+Input: nums = [1,2,2,4]
+Output: [2,3]
+
+Example 2:
+Input: nums = [1,1]
+Output: [1,2]
+
+Constraints:
+2 <= nums.length <= 104
+1 <= nums[i] <= 104
+*/
+
+class Solution
+{
+public:
+  vector<int> findErrorNums(vector<int> &nums)
+  {
+    unordered_map<int, int> freq;
+    vector<int> ans;
+
+    for (auto &i : nums)
+      freq[i]++;
+    for (auto &i : freq)
+      if (i.second == 2)
+        ans.push_back(i.first);
+    for (auto i = 1; i <= nums.size(); ++i)
+      if (freq[i] == 0)
+        ans.push_back(i);
+
+    return ans;
+  }
+};

Leetcode Daily Challenge/March-2021/README.md

@@ -3,3 +3,4 @@
 | Day | Question Links                                                                                                                         |                Solutions                |
 | :-: | :------------------------------------------------------------------------------------------------------------------------------------- | :-------------------------------------: |
 | 1.  | [Distribute Candies](https://leetcode.com/explore/challenge/card/march-leetcoding-challenge-2021/588/week-1-march-1st-march-7th/3657/) | [cpp](./01.%20Distribute%20Candies.cpp) |
+| 2.  | [Set Mismatch](https://leetcode.com/explore/challenge/card/march-leetcoding-challenge-2021/588/week-1-march-1st-march-7th/3658/)       |    [cpp](./02.%20Set%20Mismatch.cpp)    |