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原题题目

代码实现（首刷自解）

class Solution {   public:    void backtracking(vector
   
    & ret,const vector
    
     & time,int times,int turnedOn,int hour,int minute,int pos)    {           if(hour >= 12 || minute >= 60)  return;        if(times == turnedOn)        {               string temp;            temp += to_string(hour);            temp += ':';            if(minute < 10) temp+='0';            temp += to_string(minute);            ret.emplace_back(temp);            return;        }        if(pos >= time.size())  return;        for(int i=pos;i
     
       readBinaryWatch(int turnedOn) {           vector
      
        ret;        vector
       
         time{   1,2,4,8,1,2,4,8,16,32};        backtracking(ret,time,0,turnedOn,0,0,0);        return ret;    }};