Longest Common Prefix - Javacript

Write a function to find the longest common prefix string amongst an array of strings.

Tags

String

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Using the first one as the target.

Compare vertically from the start of each string.

If meets the end of the string or no longer equal. Return.

/** * @param {string[]} strs * @return {string} */// Solution 1var longestCommonPrefix = function (strs) {    var strnum = strs.length;    if (strnum === 0) {        return "";    } else if (strnum === 1) {        return strs[0];    }    var prefix = strs[0];    for (var i = 1; i < strnum; i++) {        var len = Math.min(prefix.length, strs[i].length);        for (var j = 0; j < len; j++) {            if (prefix[j] !== strs[i][j]) {                break;            }        }        prefix = prefix.substring(0, j);    }    return prefix;};// Solution 2/** * @param {string[]} strs * @return {string} */var longestCommonPrefix = function (strs) {    var len = strs.length;    if (len === 0) {        return "";    }    if (len === 1) {        return strs[0];    }    // Guarantee there are at lease 2 strings    var ret = "";    for (var index = 0; ; index++) {        var target = strs[0][index];        for (var i = 1; i < len; i++) {            if (strs[i][index] !== target || index >= strs[i].length) {                return ret;            }        }        ret += target;    }    return ret;};