Leetcode 1450. Number of Students Doing Homework at a Given Time

題目

Input: startTime = [1,2,3], endTime = [3,2,7], queryTime = 4
Output: 1
Explanation: We have 3 students where:
The first student started doing homework at time 1 and finished at time 3 and wasn't doing anything at time 4.
The second student started doing homework at time 2 and finished at time 2 and also wasn't doing anything at time 4.
The third student started doing homework at time 3 and finished at time 7 and was the only student doing homework at time 4.

解法思維

做出endTime到startTime的陣列在查找

var busyStudent = function(startTime, endTime, queryTime) {
    let sum=0
    for (let j = 0; j < startTime.length; j++) {
        let len=endTime[j]-startTime[j]
        if(len==0){
            Array.from({length:1},(v,i)=>endTime[j]).indexOf(queryTime)!=-1?sum++:false;
        }else{
            Array.from({length:len+1}, (v, i) => startTime[j]++).indexOf(queryTime)!=-1?sum++:false;
        }
    }
    return sum
};

如果startTime小於目標時間和endTime大於目標時間，就代表目標時間包含在裡面

const busyStudent = (startTime, endTime, queryTime) => {
  let ret = 0;
  for (let i = 0; i < startTime.length; ++i) {
    startTime[i] <= queryTime && endTime[i] >= queryTime && ++ret;
  }
  return ret;
};