15 Jun 2024•C++ / Python / TypeScript•Easy

Missing Number

Collected C++, Python, TypeScript solutions for missing number. Add a dedicated write-up later if you want deeper notes.

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auto-generated entry for Missing Number. the solution files are available below.

solution files

C++ missing-number/synced-solution.cpp
Python missing-number/synced-solution.py
TypeScript missing-number/synced-solution.ts

Solution files

Python•missing-number/synced-solution.py

def missingNumber(nums: list[int]) -> int:
    n = len(nums)
    expected_sum = n * (n + class="syntax-number">1) class=class="syntax-string">"syntax-comment">// class="syntax-number">2
    actual_sum = sum(nums)
    return expected_sum - actual_sum

C++•missing-number/synced-solution.cpp

class Solution {
public:
    int missingNumber(vector<int>& nums) {
        int n = nums.size();
        long long expectedSum = (long long)n * (n + class="syntax-number">1) / class="syntax-number">2;
        long long actualSum = class="syntax-number">0;
        for (int num : nums) {
            actualSum += num;
        }
        return expectedSum - actualSum;
    }
};

TypeScript•missing-number/synced-solution.ts

function missingNumber(nums: number[]): number {
    const n = nums.length;
    const expectedSum = (n * (n + class="syntax-number">1)) / class="syntax-number">2;
    const actualSum = nums.reduce((a, b) => a + b, class="syntax-number">0);
    return expectedSum - actualSum;
}