找出时针和分针之间的角度为 theta 的时间

给定角度 theta，找到时针和时钟指针之间的角度为 theta 时的可能时间（以 hh:mm 格式）。如果不存在这样的时间，则打印 -1。

例子 ：

Input : theta = 90.0
Output : 3:0 

Input : theta = 60.0
Output : 2:0

我们已经讨论了如何在下面的帖子中找到给定时间的角度。
计算时针和分针之间的角度

在这个问题中，我们被要求做反向。由于小时有 12 种可能性，分钟有 60 种可能性，我们循环遍历所有可能的时间，即 12*60 = 720，如果任何时间的角度等于给定的 theta，则我们打印该时间。

C++

// C++ program to find time for a given angle.
#include 
using namespace std;
 
// function to find angle between
// hour hand and minute hand
float calcAngle(int hh, int mm)
{
    // Calculate the angles moved by hour and
    // minute hands with reference to 12:00
    float hour_angle = 0.5 * (hh*60 + mm);
    float minute_angle = 6*mm;
 
    // Find the difference between two angles
    float angle = abs(hour_angle - minute_angle);
 
    // Return the smaller angle of two possible
    // angles
    angle = min(360-angle, angle);
 
    return angle;
}
 
// function to print all time when angle between
// hour hand and minute hand is theta
void printTime(float theta)
{
    for (int hh=0; hh<12; hh++)
    {
        for (int mm=0; mm<60; mm++)
        {
            if (calcAngle(hh, mm)==theta)
            {
                printf("%d:%d\n", hh, mm);
                return;
            }
        }
    }
    printf("Input angle not valid.\n");
    return;
}
 
// driver code to test above function
int main()
{
    float theta = 90.0;
    printTime(theta);
    return 0;
}

Java

// Java program to find time
// for a given angle.
class GFG
{
// function to find angle between
// hour hand and minute hand
static float calcAngle(int hh, int mm)
{
    // Calculate the angles moved by hour and
    // minute hands with reference to 12:00
    float hour_angle = 0.5f * (hh * 60 + mm);
    float minute_angle = 6 * mm;
 
    // Find the difference between two angles
    float angle = Math.abs(hour_angle - minute_angle);
 
    // Return the smaller angle of
    // two possible angles
    angle = Math.min(360-angle, angle);
 
    return angle;
}
 
// function to print all time when
// angle between hour hand and minute
// hand is theta
static void printTime(float theta)
{
    for (int hh = 0; hh < 12; hh++)
    {
        for (int mm = 0; mm < 60; mm++)
        {
            if (calcAngle(hh, mm) == theta)
            {
                System.out.println(hh + ":" + mm);
                return;
            }
        }
    }
     
    System.out.println("Input angle not valid.");
    return;
}
 
// Driver code
public static void main (String[] args)
{
    float theta = 90.0f;
    printTime(theta);
}
}
 
// This code is contributed by Anant Agarwal.

Python3

# Python 3 program to find time for a
# given angle.
 
# function to find angle between
# hour hand and minute hand
def calcAngle(hh, mm):
 
    # Calculate the angles moved by
    # hour and minute hands with
    # reference to 12:00
    hour_angle = 0.5 * (hh * 60 + mm)
    minute_angle = 6 * mm
 
    # Find the difference between
    # two angles
    angle = abs(hour_angle - minute_angle)
 
    # Return the smaller angle of two
    # possible angles
    angle = min(360 - angle, angle)
 
    return angle
 
# function to print all time when
# angle between hour hand and minute
# hand is theta
def printTime(theta):
 
    for hh in range(0, 12):
        for mm in range(0, 60):
            if (calcAngle(hh, mm)==theta):
                print(hh, ":", mm, sep = "")
                return
             
    print("Input angle not valid.")
    return
 
# driver code to test above function
theta = 90.0
printTime(theta)
 
# This code is contributed by Smitha

C#

// C# program to find time for a given
// angle.
using System;
 
class GFG {
 
    // function to find angle between
    // hour hand and minute hand
    static float calcAngle(int hh, int mm)
    {
         
        // Calculate the angles moved by hour
        // and minute hands with reference
        // to 12:00
        float hour_angle = 0.5f * (hh * 60 + mm);
        float minute_angle = 6 * mm;
     
        // Find the difference between two angles
        float angle = Math.Abs(hour_angle
                                 - minute_angle);
     
        // Return the smaller angle of
        // two possible angles
        angle = Math.Min(360 - angle, angle);
     
        return angle;
    }
     
    // function to print all time when
    // angle between hour hand and minute
    // hand is theta
    static void printTime(float theta)
    {
        for (int hh = 0; hh < 12; hh++)
        {
            for (int mm = 0; mm < 60; mm++)
            {
                if (calcAngle(hh, mm) == theta)
                {
                    Console.WriteLine(hh + ":" + mm);
                    return;
                }
            }
        }
         
        Console.WriteLine("Input angle not valid.");
        return;
    }
     
    // Driver code
    public static void Main ()
    {
        float theta = 90.0f;
         
        printTime(theta);
    }
}
 
// This code is contributed by vt_m.

Javascript

 
      // JavaScript program to find
      // time for a given angle.
      // function to find angle between
      // hour hand and minute hand
      function calcAngle(hh, mm)
      {
        // Calculate the angles moved by hour and
        // minute hands with reference to 12:00
        var hour_angle = 0.5 * (hh * 60 + mm);
        var minute_angle = 6 * mm;
 
        // Find the difference between two angles
        var angle = Math.abs(hour_angle - minute_angle);
 
        // Return the smaller angle of two possible
        // angles
        angle = Math.min(360 - angle, angle);
 
        return angle;
      }
 
      // function to print all time
      // when angle between
      // hour hand and minute hand is theta
      function printTime(theta) {
        for (var hh = 0; hh < 12; hh++)
        {
          for (var mm = 0; mm < 60; mm++)
          {
            if (calcAngle(hh, mm) === theta)
            {
              document.write(hh + ":" + mm + "<br>");
              return;
            }
          }
        }
        document.write("Input angle not valid.<br>");
        return;
      }
 
      // driver code to test above function
      var theta = 90.0;
      printTime(theta);
       

输出 ：

3:0

时间复杂度：O(1)
辅助空间：O(1)