Longest Common Prefix (Java)

Leetcode

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

	/*
	Write a function to find the longest common prefix string amongst an array of strings.
	*/
	// rewrite at 2/28/2014
	public class Solution {
	public String longestCommonPrefix(String[] strs) {
	if (strs==null||strs.length==0){
	return "";
	}
	if (strs.length==1){
	return strs[0];
	}
	String str=strs[0];
	for (int i=0; i<str.length(); i++){
	char c=str.charAt(i);
	for (int j=1; j<strs.length; j++){
	if (strs[j].length()==i || strs[j].charAt(i)!=c){
	return str.substring(0, i);
	}
	}
	}
	return str;
	}
	}
	// old version
	public class Solution {
	public String longestCommonPrefix(String[] strs)
	{
	if (strs.length==0) return “”;
	int index=0;
	while (index<strs[0].length())
	{
	char c=strs[0].charAt(index);
	for (int i=1; i<strs.length;i++)
	{
	// Don’t forget to also check if index out of range of other str in strs beside strs[0]
	if (index==strs[0].length()||index==strs[i].length()||strs[i].charAt(index)!=c)
	{
	return strs[0].substring(0,index);
	}
	}
	index++;
	}
	return strs[0];
	}
	}

view raw Longest common prefix.java hosted with ❤ by GitHub