Longest Common Prefix
Description
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: strs = ["flower","flow","flight"] Output: "fl"
Example 2:
Input: strs = ["dog","racecar","car"] Output: "" Explanation: There is no common prefix among the input strings.
Constraints:
1 <= strs.length <= 200
0 <= strs[i].length <= 200
strs[i]
consists of only lower-case English letters.
Solution(javascript)
/**
* @param {string[]} strs
* @return {string}
*/
var longestCommonPrefix = function(strs) {
// If the string is empty return empty string
if (strs.length === 0) return "";
// The prefix is the start of the word
let prefix = strs[0];
// Iterate over the array
for (let i = 1; i < strs.length; i++)
// Returns -1 or 0. 0 if the char matches the prefix
while (strs[i].indexOf(prefix) !== 0) {
// slices the prefix from the start to the char
prefix = prefix.substring(0, prefix.length - 1);
if (prefix.length === 0) return "";
}
return prefix;
};
// Time: O(n), where n is the sum of all the characters in all strins
// Space: O(1)