JavaScript-Interview-Questions/recursion/011.js at master · devangnpatil/JavaScript-Interview-Questions · GitHub

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* <!--

* This program is distributed under

* the terms of the MIT license.

* Please see the LICENSE file for details.

* -->

* Write an iterative method to generate nth Fibonacci number.

* F(n) = F(n-1) + F(n-1); F(0) == 0, F(1) == 1;

/*____________________________________________________________________________*/

function fibonacci(n) {

if (n === 0) {

return 0;

}

if (n === 1) {

return 1;

}

if (n < 1) {

return -1;

}

var i = 0;

var c = 0;

var a = 1;

var b = 1;

for (i = 3; i <= n; i++) {

c = a + b;

a = b;

b = c;

}

return b;

}

/*____________________________________________________________________________*/

console.log( fibonacci(99) );

Output: ($ /usr/bin/node 011.js)

218922995834555200000

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