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LeetCode solutions

1146. Greatest Common Divisor of Strings

My accepted C++ solution to LeetCode problem 1146, Greatest Common Divisor of Strings, running in 0ms.

  • Difficulty: Easy
  • C++
  • Runtime 0ms
  • Memory 9.7MB

Read the problem on LeetCode View on GitHub

The problem statement is LeetCode’s and stays on their site. What follows is my accepted solution.

C++

Accepted on LeetCode — runtime 0ms, memory 9.7MB, accepted 2025-12-28.

cpp
class Solution {
public:
    string gcdOfStrings(string str1, string str2) {
        // If there's a common divisor, str1 + str2 == str2 + str1
        if (str1 + str2 != str2 + str1) return "";
        // The GCD of lengths gives us the length of the result
        return str1.substr(0, __gcd((int)str1.size(), (int)str2.size()));
    }
};

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