tsanmmmm2000's Tech Blog

Question

Write a function to find the longest common prefix string amongst an array of strings.

My C# Solution

public class Solution {
    public string LongestCommonPrefix(string[] strs) {
        
        if (strs.Length == 0) return string.Empty;
        var firstItem = strs[0];
        if (strs.Length == 1) return firstItem;

        var length = firstItem.Length;
        for(var i = 1; i < strs.Length; i++)
        {
            var item = strs[i];
            length = (length > item.Length) ? item.Length : length;
            while(item.Substring(0, length) != firstItem.Substring(0, length) 
                && length > 0)
            {
                length--;
            }
            
            if (length == 0)
            {
                return string.Empty;
            }
        }
        return firstItem.Substring(0, length);
    }
}