Cinte's Leetcode Record
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面试题 08.05. 递归乘法

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Symbols count in article: 359 Reading time ≈ 1 mins.

面试题 08.05. 递归乘法

又是一个我很菜的见证

迭代

二进制乘法

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class Solution {
public:
    int multiply(int A, int B) {
        long ret = 0;
        while(B)
        {
            if(B & 1)
                ret += A;
            A <<= 1;
            B >>= 1;
        }
        return ret;
    }
};
递归
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class Solution {
public:
    int multiply(int A, int B) {
        if(!B)
            return 0;
        long ret = B & 1 ? A : 0;
        ret += multiply(A << 1, B >> 1);
        return ret;
    }
};