题解 | #牛群字母的集合#
牛群字母的集合
https://www.nowcoder.com/practice/5aa097cccc0241febe1054bd85ce299b
function cowCombination( s ) { // write code here let ans = [] const tracingback = (path,idx) => { ans.indexOf(path.join("")) == "-1" && ans.push(path.join("")) for(let i=idx;i<s.length;i++) { path.push(s[i]) tracingback(path,i+1) path.pop() } } tracingback([],0) return ans }