Rod cutting question using recursion

, ,
1

hey there.I am a beginner and i am learning recursion these days.
I came across with this problem.And i am having some queries.

#include <bits stdc++.h>
using namespace std;

int rodCutting(int n, int a, int b, int c)
{
if(n == 0)
return 0;
if(n < 0)
return -1;
int res = max(max(rodCutting(n-a, a, b, c), rodCutting(n-b, a, b, c)),
rodCutting(n-c, a, b, c));

if(res== -1)
return -1;
return 1+res;
}

int main()
{
int n = 25;
int a = 11, b = 12, c = 13;
cout << rodCutting(n, a, b, c);
}

please explain me how return res+1 is working.I mean we are initializing it again and again how it is incrementing its value??? Please help!!!

2

As you are calling function recursively each function will have its own res variable and the res which you are returning gets initialized to the local res of that function.

1 Like
3

Can you explain it with an example???or Any link or article by which i can understand it better. @khan_rahim

4

can you explain how by debugging this code for-
n=5 a=2 b=1 c=5
we are getting 5 as output by this code.