面试题38. 字符串的排列

[fireairforce]

dfs回溯，记得去重

/**
 * @param {string} s
 * @return {string[]}
 */
var permutation = function(s) {
  s = s.split('')
  let res = []
  const dfs = (s,tempList,visited) => {
      if(tempList.length === s.length) {
          res.push([...tempList]);
          return;
      }
      for(let i = 0;i<s.length;i++) {
          if(visited[i]) {
              continue;
          }
          if(i > 0 && s[i] === s[i-1] && visited[i-1]) {
              continue;
          }
          visited[i] = true;
          tempList.push(s[i]);
          dfs(s,tempList,visited);
          visited[i] = false;
          tempList.pop();
      }
  }
  dfs(s.sort((a,b)=>a-b),[],[]);
  for(let i = 0;i<res.length;i++) {
      res[i] = res[i].join('')
  }
  return Array.from(new Set(res))
};
// permutation("suvyls")