470. Implement Rand10() Using Rand7()
Description
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()
?
Solutions
Solution 1
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1 2 3 4 5 6 7 8 9 10 |
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 |
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 |
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