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[!info] related notes 算法面试题型 MOC 回溯

电话号码的字母组合

题目

17. 电话号码的字母组合 - 力扣（LeetCode）

题解

链表-二叉树-回溯

var letterCombinations = function(digits) {
    const MAPPING = ["", "", "abc", "def", "ghi", "jkl", "mno", "pqrs", "tuv", "wxyz"];
    const n = digits.length;
    if (n === 0) {
        return [];
    }
    const path = Array(n);
    const ans = [];
    function dfs(i) {
        if (i === n) {
            ans.push(path.join(""));
            return;
        }
        const letters = MAPPING[Number(digits[i])];
        for (const c of letters) {
            path[i] = c;
            dfs(i + 1);
        }
    }
    dfs(0);
    return ans;
};

参考