题目描述
Given a function rand7 which generates a uniform random integer in the range 1 to 7, write a function rand10 which generates a uniform random integer in the range 1 to 10.
Do NOT use system's Math.random().
Example 1:
Input: 1
Output: [7]
Example 2:
Input: 2
Output: [8,4]
Example 3:
Input: 3
Output: [8,1,10]
题目思路
代码 C++
- 思路一、
// The rand7() API is already defined for you.
// int rand7();
// @return a random integer in the range 1 to 7
class Solution {
public:
int rand10() {
int result = 7 * (rand7() - 1) + rand7();
while(result > 40){
result = 7 * (rand7() - 1) + rand7();
}
return result%10 + 1;
}
};
总结展望
- 已知random7求random10