Sword finger offer cut rope

Title Description

I'll give you a length of n The rope of , Please cut the rope into m paragraph （m、n Are integers. ,n>1 also m>1）, The length of each rope is recorded as k[0],k[1],...,k[m]. Excuse me, k[0]xk[1]x...xk[m] What's the maximum possible product ？ for example , When the length of the rope is 8 when , We cut it into lengths of 2、3、3 Three paragraphs of , The maximum product we get here is 18

 

Multiplication , Except one , The more numbers you multiply, the greater the result
from 2 Begin to think about , If you use 2 piecewise , The existence of odd numbers will leave one 2,1, At this time
It should be replaced by 3, therefore 2,3 piecewise
2*2*2<3*3, Should let 3 As much as possible
Usage %3, Remainder is 2 There is a 2, by 1 There are two 2 

class Solution {
public:
    int cutRope(int target) {
        if(target<=3)return target-1;
        int res=1;//%3=0
        if(target%3==1){
          res=4;
          target-=4;
        }else if(target%3==2){
          res=2;
          target-=2;
        }
        while(target){
          res*=3;
          target-=3;
        }
        return res;
    }
};