[GeeksForGeeks] Multiply a given integer by 3.5

转载于 2017-07-20 06:53:00 发布 · 78 阅读

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原文链接：http://www.cnblogs.com/lz87/p/7209117.html

本文介绍了一种不使用%、/或*运算符实现整数与3.5相乘的方法。通过位操作（左移和右移）实现乘法，提供了具体的Java代码示例并进行了验证。

Given an integer x, write a method that multiplies x with 3.5 and returns the integer result. You are not allowed to use %, /, or *.

Examples: input 2, output 7; input 5, output 17

Solution. Use left shift and right shift operators.

 1 public class Solution {
 2     public int multiply3point5(int x){
 3         return (x << 1) + x + (x >> 1);
 4     }
 5     public static void main(String[] args){
 6         Solution sol = new Solution();
 7         assert sol.multiply3point5(2) == 7;
 8         assert sol.multiply3point5(5) == 17;
 9     }
10 }