P014 Longest Common Prefix

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

思路分析

题目本身并不难，最直观的就是逐个字符比较。操作下标很费劲。

  • 最长前缀的长度不会超过某个字符串的长度

代码

java

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public class Solution014 {
	public String longestCommonPrefix(String[] strs) {
		StringBuilder sb = new StringBuilder();
		if (strs == null || strs.length == 0)
			return "";
		if (strs.length == 1)
			return strs[0];
		for (int i = 0; i < strs[0].length(); i++) {
			char c = strs[0].charAt(i);
			for (int j = 1; j < strs.length; j++) {
				if (strs[j].length() == i || c != strs[j].charAt(i)) {
					return sb.toString();
				}
			}
			sb.append(c);
		}
		return sb.toString();
	}
}

python

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class Solution014(object):
    def longestCommonPrefix(self, strs):
        """
        :type strs: List[str]
        :rtype: str
        """
        l = len(strs)
        if not strs or l == 0:return ""
        if l == 1:return strs[0]
        
        ret = ""
        for i in range(0, len(strs[0])):
            c = strs[0][i]
            for j in range(1, l):
                if len(strs[j]) == i or c != strs[j][i]:
                    return ret
            ret += c;
            
        return ret