412. Fizz Buzz.md

412. Fizz Buzz

思路

这题很简单，我们可以用for循环从i=1到i=n，然后判断i是否是3或者5的倍数。

评论区说因为取余操作%比较费时，所以我们应该避免取余，下面代码给出了两种避免取余的思路，亲测确实比直接取余要快一点点。

C++

class Solution {
public:
    vector<string> fizzBuzz(int n) {
        vector<string>res(n);
        for(int i = 1; i <= n; i++) res[i-1] = to_string(i);
        for(int i = 2; i < n; i+=3) res[i] = "Fizz";
        for(int i = 4; i < n; i+=5) res[i] = "Buzz";
        for(int i = 14; i < n; i+=15) res[i] = "FizzBuzz";

        return res;
    }
};

class Solution {
public:
    vector<string> fizzBuzz(int n) {
        vector<string>res(n);
        
        int fizz = 3, buzz = 5;
        for(int i = 1; i <= n; i++){
            if(i == fizz){
                res[i-1] = "Fizz";
                fizz += 3;
                if(i == buzz){
                    buzz += 5;
                    res[i-1] += "Buzz";
                }
            }
            else if(i == buzz){
                    buzz += 5;
                    res[i-1] = "Buzz";
            }
            else res[i-1] = to_string(i);
        }

        return res;
    }
};