Rabbits

#include <bits/stdc++.h>
#define ll long long int
using namespace std;

ll rabbits(int month, map<int, ll>& memo) {
    if (month == 0) return 0;
    if (month == 1) return 1;

    if (memo.find(month) != memo.end()) return memo[month];

    memo[month] = rabbits(month - 1, memo) + rabbits(month - 2, memo);
    return memo[month];
}

int main() {
    int a, b;
    cin >> a >> b;

    map<int, ll> memo; 

    int month = 0;
    int sol = 0;
    ll num_rabbits = 0;

    while (num_rabbits < b) {
        num_rabbits = rabbits(month, memo);  
        if (num_rabbits >= a) {
            ++sol;
        }
        ++month;
    }

    cout << sol << endl;
    return 0;
}

Test 1

Verdict: WRONG ANSWER

Test 2

Verdict: WRONG ANSWER

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: WRONG ANSWER

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: WRONG ANSWER

Test 13

Verdict: WRONG ANSWER

Test 14

Verdict: ACCEPTED

Test 15

Verdict: WRONG ANSWER

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: WRONG ANSWER

Test 19

Verdict: WRONG ANSWER

Test 20

Verdict: WRONG ANSWER

Test 21

Verdict: ACCEPTED

Test 22

Verdict: ACCEPTED

Test 23

Verdict: ACCEPTED