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
利用index of判断是不是含有这个前缀,不包含时一直从后往前减小长度
遍历,维护一个最大的res即为答案,其会是所有的公共前缀
Code
class Solution {
public String longestCommonPrefix(String[] strs) {
if (strs == null || strs.length == 0 ) return "";
String res = strs[0];
for (int i = 1; i < strs.length; i++) {
while (strs[i].indexOf(res) != 0) {
res = res.substring(0, res.length() - 1);
}
}
return res;
}
}
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