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  1. //Fibonacci number using memoization.
  2. #include<bits/stdc++.h>
  3. using namespace std;
  4.  
  5. int fibRec(int n, vector<int> &mem) {
  6.  
  7.     // Base case
  8.     if (n <= 1) {
  9.         return n;
  10.     }
  11.  
  12.     // To check if output already exists
  13.     if (mem[n] != -1) {
  14.         return mem[n];
  15.     }
  16.  
  17.     // Calculate and save output for future use
  18.     mem[n] = fibRec(n - 1, mem) + fibRec(n - 2, mem);
  19.  
  20.     return mem[n];
  21. }
  22.  
  23. int fib(int n) {
  24.     vector<int> mem(n + 1, -1);
  25.     return fibRec(n, mem);
  26. }
  27.  
  28. int main() {
  29.     int n = 10;
  30.     cout << fib(n);
  31.     return 0;
  32. }
Success #stdin #stdout 0.01s 5284KB
comments (?)
stdin 
Standard input is empty
stdout 
55
https://ideone.com/XIFDms
Fibonacci number using memoization.
language:
C++14 (gcc 8.3)
created:
1 year ago
visibility:
public

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