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@rexfordkelly
Last active April 22, 2017 19:33
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Examples of implementing iterative solutions for fib in js
**Fib Explored.**
The following is based on some notes i've made while working through fib toy problems with others.
```
/**
Simple iterative Fib sequence generator
*/
function fib_seq(n){
var i = 1;
var s = [1,1];
while ( ++i <= n ){ // How many times will this loop run? Hint: n + 1 (for zero) - 2, or n - 1 times.
s[i] = s[ i-2 ] + s[ i-1 ];
}
return (n < 0) ? undefined : s; // if n was less than 0, we return undefined, otherwise the full sequence we builtup.
}
/**
Simple iterative last Fib calculator
*/
function last_fib( n ){
var a,b,f,i;
a = 0, b = f = i = 1;
do {
f = (( a = b ) + ( b = f )); // Why does this work? hint: what do "()" mean in this expression.
} while( ++i < n );
return n > 1 ? f : 1;
}
```
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