Q13: Longest Common Prefix. - DSA Patterns (Multi-Lang)

In Simple Words: Compare characters vertically across all strings at index $0, 1, 2, \dots$. The moment any string ends or a character mismatch occurs, return prefix up to that point.

Time: $O(N \cdot M)$ | Space: $O(1)$

Multi-Language SolutionsPython 3 • JavaScript • TypeScript • Java • C++

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def longestCommonPrefix(strs: list[str]) -> str:
    if not strs:
        return ""
    for i in range(len(strs[0])):
        c = strs[0][i]
        for s in strs[1:]:
            if i == len(s) or s[i] != c:
                return strs[0][:i]
    return strs[0]