Algorithm
Problem Name: 645. 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 <= 1041 <= nums[i] <= 104
Code Examples
#1 Code Example with C++ Programming
Code -
C++ Programming
class Solution {
public:
vector<int> findErrorNums(vector<int>& nums) {
int n = nums.size(), sum = 0, dup = 0, miss = 0;
vector<int>count(n, 0);
for(int i = 0; i < n; sum += nums[i++]) if(++count[nums[i] - 1] > 1) dup = nums[i];
miss = n * (n + 1) / 2 - sum + dup;
return {dup, miss};
}
};
Input
Output
#2 Code Example with Java Programming
Code -
Java Programming
class Solution {
public int[] findErrorNums(int[] nums) {
int[] result = new int[2];
Set < Integer> set = new HashSet<>();
int n = nums.length;
for (int num : nums) {
if (!set.add(num)) {
result[0] = num;
}
}
for (int i = 1; i < = n; i++) {
if (!set.contains(i)) {
result[1] = i;
}
}
return result;
}
}
Input
Output
#3 Code Example with Javascript Programming
Code -
Javascript Programming
const findErrorNums = function(nums) {
if(nums == null || nums.length === 0) return null
const res = []
const hash = {}
for(let el of nums) {
if(hash.hasOwnProperty(el)){
res[0] = el
} else hash[el] = 0
hash[el]++
}
for(let i = 1, len = nums.length; i <= len; i++) {
if(!hash.hasOwnProperty(i)> {
res[1] = i
break
}
}
return res
};
Input
Output
#4 Code Example with Python Programming
Code -
Python Programming
class Solution:
def findErrorNums(self, nums: List[int]) -> List[int]:
cnt = collections.Counter(nums)
return [k for k in cnt if cnt[k] == 2] + [i for i in range(1, len(nums) + 1) if i not in cnt]
Input
Output
#5 Code Example with C# Programming
Code -
C# Programming
using System;
namespace LeetCode
{
public class _0645_SetMismatch
{
public int[] FindErrorNums(int[] nums)
{
int duplicate = -1, missing = -1;
foreach (int num in nums)
{
if (nums[Math.Abs(num) - 1] < 0)
duplicate = Math.Abs(num);
else
nums[Math.Abs(num) - 1] *= -1;
}
for (int i = 0; i < nums.Length; i++)
if (nums[i] > 0)
missing = i + 1;
return new int[] { duplicate, missing };
}
}
}
Input
Output