Fibonacci Number

 Fibonacci Number

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Given a number N, figure out if it is a member of fibonacci series or not. Return true if the number is member of fibonacci series else false.

Fibonacci Series is defined by the recurrence

    F(n) = F(n-1) + F(n-2)

where F(0) = 0 and F(1) = 1

Input Format :

Integer N

Output Format :

true or false

Constraints :

0 <= n <= 10^4

Sample Input 1 :

5

Sample Output 1 :

true

Sample Input 2 :

14

Sample Output 2 :

false    

bool checkMember(int n){
  /* Don't write main().
   * Don't read input, it is passed as function argument.
   * Return output and don't print it.
   * Taking input and printing output is handled automatically.
  */
   
// int a=0;
// int b=1;
// int c;
// int start=0;
// while(start<n){
//  c=a+b;
//  a=b;
//  b=c;
//     if(c==n){
//         return true;
//     }
//   start++;  
// }
//     return false;
    int f1=0,f2=1,fib;
    //cin>>n;
    for(int i=0;i<n;i++){
        fib=f1+f2;
        f1=f2;
        f2=fib;
        
    }
    return fib==n;
}