最后一遍-L14-Longest Common Prefix
Write a function to find the longest common prefix string amongst an array of strings.
If there is no common prefix, return an empty string "".
Example 1:
Input: ["flower","flow","flight"]
Output: "fl"
Example 2:
Input: ["dog","racecar","car"]
Output: ""
Explanation: There is no common prefix among the input strings.
Note:
All given inputs are in lowercase letters a-z.
转化，理解题意
代码：
import org.apache.isis.core.commons.ensure.Assert;
public class L14 {
public static void main(String[] args) {
Assert.assertEquals("dd","dd");
Assert.assertEquals(L14.longestCommonPrefix(new String[]{}), "");
Assert.assertEquals(L14.longestCommonPrefix(new String[]{"abcde"}), "abcde");
Assert.assertEquals(L14.longestCommonPrefix(new String[]{"abcde","abcded"}), "abcde");
}
public static String longestCommonPrefix(String[] strs) {
if(strs == null || strs.length==0) return "";
if(strs.length == 1) return strs[0];
StringBuilder result = new StringBuilder();
for (int i = 0; i < strs[0].toCharArray().length;i++) {
Character indexchar = strs[0].toCharArray()[i];
boolean equal = true;
for(int j=1;j < strs.length;j++){
equal = equal && i < strs[j].length() && strs[j].charAt(i) == indexchar;
if(!equal) break;
}
if(equal){
result.append(indexchar);
}else{
break;
}
}
return result.toString();
}
}
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