# LeetCode - 0470. Implement Rand10() Using Rand7() ### 題目網址:https://leetcode.com/problems/implement-rand10-using-rand7/ ###### tags: `LeetCode` `Medium` `模擬` `數學` ```cpp= /* -LeetCode format- Problem: 470. Implement Rand10() Using Rand7() Difficulty: Medium by Inversionpeter */ // 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() { static int result; do { result = rand7() + rand7() * 7; } while (result > 47); return result % 10 + 1; } }; ```