Question

f(n) ={n/2. if n is even ,3n+1.if n is odd​

Answer 1

Step-by-step explanation:

f 0 vote

My answer in C++

I got 261 as a result...not sure if it's correct

#include <iostream>

#include <unordered_map>

using namespace std;

unordered_map<int, int> col;

unordered_map<int, int> path_length;

int F(int n)

{

if (col.count(n) != 0)

return col[n];

if (n % 2 == 0)

col.insert({ n, n / 2 });

else

col.insert({ n, (3 * n + 1) });

return col[n];

}

int FindPathLength(int num )

{

if (path_length.count(num) != 0)

return path_length[num];

int f = F(num);

if (f == 1)

{

path_length.insert({ num, 0 });

return 1;

}

int r = FindPathLength(f);

path_length.insert({ f, r });

return (1 + r);

}

int GetLongestCollapseSequence(int n)

{

int max = INT_MIN;

for (int i = 1; i < n; ++i)

{

//cout << i << endl;

int curr = FindPathLength(i);

if (curr > max)

{

max = curr;

//cout << "max is now " << max << " for i " << i << endl;

}

}

return max;

}

void main_collapse_seq(void)

{

cout << GetLongestCollapseSequence(10000)<< endl;

}

- A July 05, 2017 | Flag