[LeetCode] 681. Next Closet Time

• Problem: 681. Next Closet Time 下個最接近的時間
• Limitation: 只能用原本時間的 digits, 可以重複
• Concept: 
• string/char/time 操作
• 可以直接暴力的使用累加來比對是否符合條件, 因為最大值僅 60 * 24 (=1440)
• Note: includes 的 parameter 僅能用以排序的 container, e.g. set

• class Solution {
  public:
      string nextClosestTime(string time) {
          string nextTime = time;
          
          // brute force to incremental check
          set setTimeChar(time.begin(), time.end());
  
          int hours = stoi(time.substr(0, 2));
          int mins = stoi(time.substr(3, 2));
  
          const int MAX_NEXT_TIME = 60 * 24;
          
          for (int i = 0; i < MAX_NEXT_TIME; i++) {
              if(++mins >= 60) {
                  mins -= 60;
                  ++hours;
                  if (hours >= 24)
                      hours -= 24;
              };
              
              const int TIME_LEN = 5;
              char buf[TIME_LEN];
              sprintf(buf, "%02d:%02d", hours, mins);
              set setNextTimeChar(buf, buf + TIME_LEN);
              if (includes(setTimeChar.begin(), setTimeChar.end(), setNextTimeChar.begin(), setNextTimeChar.end()))
                  return string(buf);
          }
          return time;
      }
  };