Package g0401_0500.s0470_implement_rand10_using_rand7

Class Solution

java.lang.Object
g0401_0500.s0470_implement_rand10_using_rand7.Solution
public class Solution extends java.lang.Object
470 - Implement Rand10() Using Rand7().

Medium

Given the API rand7() that generates a uniform random integer in the range [1, 7], write a function rand10() that generates a uniform random integer in the range [1, 10]. You can only call the API rand7(), and you shouldn’t call any other API. Please do not use a language’s built-in random API.

Each test case will have one internal argument n, the number of times that your implemented function rand10() will be called while testing. Note that this is not an argument passed to rand10().

Example 1:

Input: n = 1

Output: [2]

Example 2:

Input: n = 2

Output: [2,8]

Example 3:

Input: n = 3

Output: [3,8,10]

Constraints:

  • 1 <= n <= 105

Follow up:

  • What is the expected value for the number of calls to rand7() function?
  • Could you minimize the number of calls to rand7()?

  • Constructor Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    rand10()
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • rand10

      public int rand10()