Problem:
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Fibonacci Number

Write a program which prints $n$-th fibonacci number for a given integer $n$. The $n$-th fibonacci number is defined by the following recursive formula:

\begin{equation*}
fib(n)= \left \{
\begin{array}{ll}
1　 & (n = 0) \\
1　 & (n = 1) \\
fib(n - 1) + fib(n - 2) & \\
\end{array}
\right.
\end{equation*}

Input

An integer $n$ is given.

output

Print the $n$-th fibonacci number in a line.

Constraints

$0 \leq n \leq 44$

Sample Input 1

3

Sample Output 1

3

Solution in C (judge verdict: Time Limit Exceeded)

#include <stdio.h>
#define N 45
int A[N];

int fibonacci(int n){
  if(n==0 || n==1){
    return 1;
  }
  else if(n >= 2)
    A[n] = fibonacci(n-1) + fibonacci(n-2);
  return A[n];
}
main(){
  int i,n,m;
  int A[N];
  for(i=0;i<N;i++){
    A[i]=0;
  }
  scanf("%d",&n);
  m = fibonacci(n);
  printf("%d\n", m);
  return 0;
}