LeetCode in TypeScript

14. Longest Common Prefix

Easy

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

function longestCommonPrefix(strs: string[]): string {
    if (strs.length < 1) {
        return ''
    }
    if (strs.length === 1) {
        return strs[0]
    }
    let temp = strs[0]
    let i = 1
    let cur: string
    while (temp.length > 0 && i < strs.length) {
        if (temp.length > strs[i].length) {
            temp = temp.substring(0, strs[i].length)
        }
        cur = strs[i].substring(0, temp.length)
        if (cur !== temp) {
            temp = temp.substring(0, temp.length - 1)
        } else {
            i++
        }
    }
    return temp
}

export { longestCommonPrefix }

This site is open source. Improve this page.