[LeetCode] 1344. Angle Between Hands of a Clock

Given two numbers, hour and minutes. Return the smaller angle (in degrees) formed between the hour and the minute hand.

Example 1:

Input: hour = 12, minutes = 30
Output: 165

Example 2:

Input: hour = 3, minutes = 30
Output: 75

Example 3:

Input: hour = 3, minutes = 15
Output: 7.5

Example 4:

Input: hour = 4, minutes = 50
Output: 155

Example 5:

Input: hour = 12, minutes = 0
Output: 0

Constraints:

1 <= hour <= 12
0 <= minutes <= 59
Answers within 10^-5 of the actual value will be accepted as correct.

时钟指针的夹角。题意很直观。

思路也很直观，首先定义好一分钟的夹角是6度，一小时的夹角是30度。接着根据这个定义分别算出时针和分针与0：00这个位置的夹角。注意最后两者的夹角一定不会大于360度。

时间O(1)

空间O(1)

Java实现

 1 class Solution {
 2     public double angleClock(int hour, int minutes) {
 3         int oneMinAngle = 6;
 4         int oneHourAngle = 30;
 5         double minutesAngle = oneMinAngle * minutes;
 6         double hoursAngle = (hour % 12 + minutes / 60.0) * oneHourAngle;
 7         double diff = Math.abs(hoursAngle - minutesAngle);
 8         return Math.min(diff, 360 - diff);
 9     }
10 }

JavaScript实现

 1 /**
 2  * @param {number} hour
 3  * @param {number} minutes
 4  * @return {number}
 5  */
 6 var angleClock = function(hour, minutes) {
 7     let oneMinuteAngle = 6;
 8     let oneHourAngle = 30;
 9     let minutesAngle = oneMinuteAngle * minutes;
10     let hoursAngle = ((hour % 12) + minutes / 60.0) * oneHourAngle;
11     let diff = Math.abs(hoursAngle - minutesAngle);
12     return Math.min(diff, 360 - diff);
13 };

LeetCode 题目总结