Climbing Stairs

A question using Memoization

Question

https://leetcode.com/problems/climbing-stairs

Soln

#include <map>
class Solution {
public:
 
std::map<int, int> mymap;
 
int climbStairs(int n) {
  if (n == 0) return 1;
  if (n < 0) return 0;
  if (! mymap[n]){
      mymap[n] = climbStairs(n-1) + climbStairs(n-2);  
  }
  return mymap[n];
  
} 
};