时针和分针角度问题 - 未名空间MITBBS历史存档

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时针和分针角度问题

时针和分针角度问题# JobHunting - 待字闺中

b*y2011-08-02 07:08

1 楼

Find the minimum angle between hour hand and minute hand in a watch. Write
an algo, code it in C, write the test cases.
总看不大明白，如果两针均匀移动，那最小角度是0啊，因为两针肯定要重合的。难道
分针只能走整数分钟？

h*n2011-08-02 07:08

2 楼

是不是说输入一个几点几分, 算一下当时手表上的时针分针中间角度啊

【在 b***y 的大作中提到】

: Find the minimum angle between hour hand and minute hand in a watch. Write
: an algo, code it in C, write the test cases.
: 总看不大明白，如果两针均匀移动，那最小角度是0啊，因为两针肯定要重合的。难道
: 分针只能走整数分钟？

b*42011-08-02 07:08

3 楼

是150题那本书里的吗？
Example: Given a time, calculate the angle between the hour and minute hands.
Approach: Start with an example like 3:27. We can draw a picture of a clock
by selecting where the 3 hour hand is and where the 27 minute hand is.
By playing around with these examples, we can develop a rule:
»»Minute angle (from 12 o’clock): 360 * minutes / 60
»»Hour angle (from 12 o’clock): 360 * (hour % 12) / 12 + 360 * (
minutes / 60) * (1 / 12)
»»Angle between hour and minute: (hour angle - minute angle) % 360
By simple arithmetic, this reduces to 30 * hours - 5.5 * minutes.

b*y2011-08-02 07:08

4 楼

如果这样就简单了，结果要取绝对值吧？

hands.
clock
360

【在 b******4 的大作中提到】

: 是150题那本书里的吗？
: Example: Given a time, calculate the angle between the hour and minute hands.
: Approach: Start with an example like 3:27. We can draw a picture of a clock
: by selecting where the 3 hour hand is and where the 27 minute hand is.
: By playing around with these examples, we can develop a rule:
: »»Minute angle (from 12 o’clock): 360 * minutes / 60
: »»Hour angle (from 12 o’clock): 360 * (hour % 12) / 12 + 360 * (
: minutes / 60) * (1 / 12)
: »»Angle between hour and minute: (hour angle - minute angle) % 360
: By simple arithmetic, this reduces to 30 * hours - 5.5 * minutes.