0014-longest-common-prefix.java

class Solution {
    public String longestCommonPrefix(String[] strs) {
        
        if (strs.length == 0) return "";
        
        String prefix = strs[0];
        
        for (int i = 1; i < strs.length; i++) {
            
            while (strs[i].indexOf(prefix) != 0) {
                
                prefix = prefix.substring(0, prefix.length() - 1);
                if (prefix.length() == 0) return "";
            }
        }
        return prefix;
    }
}