3153. Sum of Digit Differences of All Pairs LeetCode Solution

In this guide, you will get 3153. Sum of Digit Differences of All Pairs LeetCode Solution with the best time and space complexity. The solution to Sum of Digit Differences of All Pairs problem is provided in various programming languages like C++, Java, and Python. This will be helpful for you if you are preparing for placements, hackathons, interviews, or practice purposes. The solutions provided here are very easy to follow and include detailed explanations.

Table of Contents

  1. Problem Statement
  2. Complexity Analysis
  3. Sum of Digit Differences of All Pairs solution in C++
  4. Sum of Digit Differences of All Pairs solution in Java
  5. Sum of Digit Differences of All Pairs solution in Python
  6. Additional Resources
3153. Sum of Digit Differences of All Pairs LeetCode Solution image

Problem Statement of Sum of Digit Differences of All Pairs

You are given an array nums consisting of positive integers where all integers have the same number of digits.
The digit difference between two integers is the count of different digits that are in the same position in the two integers.
Return the sum of the digit differences between all pairs of integers in nums.

Example 1:

Input: nums = [13,23,12]
Output: 4
Explanation:
We have the following:
– The digit difference between 13 and 23 is 1.
– The digit difference between 13 and 12 is 1.
– The digit difference between 23 and 12 is 2.
So the total sum of digit differences between all pairs of integers is 1 + 1 + 2 = 4.

Example 2:

Input: nums = [10,10,10,10]
Output: 0
Explanation:
All the integers in the array are the same. So the total sum of digit differences between all pairs of integers will be 0.

See also  3013. Divide an Array Into Subarrays With Minimum Cost II LeetCode Solution

Constraints:

2 <= nums.length <= 105
1 <= nums[i] < 109
All integers in nums have the same number of digits.

Complexity Analysis

  • Time Complexity: O(n)
  • Space Complexity: O(10) = O(1)

3153. Sum of Digit Differences of All Pairs LeetCode Solution in C++

class Solution {
 public:
  long long sumDigitDifferences(vector<int>& nums) {
    const int n = nums.size();
    const int digitSize = std::to_string(nums[0]).size();
    long ans = 0;

    for (int i = 0, denominator = 1; i < digitSize; ++i, denominator *= 10) {
      vector<int> count(10);
      for (const int num : nums)
        ++count[num / denominator % 10];
      for (const int freq : count)
        ans += freq * (n - freq);
    }

    return ans / 2;
  }
};
/* code provided by PROGIEZ */

3153. Sum of Digit Differences of All Pairs LeetCode Solution in Java

class Solution {
  public long sumDigitDifferences(int[] nums) {
    final int n = nums.length;
    final int digitSize = String.valueOf(nums[0]).length();
    long ans = 0;

    for (int i = 0, denominator = 1; i < digitSize; ++i, denominator *= 10) {
      int[] count = new int[10];
      for (final int num : nums)
        ++count[num / denominator % 10];
      for (final int freq : count)
        ans += freq * (n - freq);
    }

    return ans / 2;
  }
}
// code provided by PROGIEZ

3153. Sum of Digit Differences of All Pairs LeetCode Solution in Python

class Solution:
  def sumDigitDifferences(self, nums: list[int]) -> int:
    n = len(nums)
    digitSize = len(str(nums[0]))
    ans = 0

    denominator = 1
    for _ in range(digitSize):
      count = [0] * 10
      for num in nums:
        count[num // denominator % 10] += 1
      ans += sum(freq * (n - freq) for freq in count)
      denominator *= 10

    return ans // 2
# code by PROGIEZ

Additional Resources

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