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Make Fibonacci.js file comply with standard JS rules

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This commit is contained in:
Rahul Jain
2020-10-30 16:08:16 +05:30
parent 78a05970e2
commit feaca3b27a
1 changed files with 22 additions and 22 deletions
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44
Maths/Fibonacci.js
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@ -72,11 +72,11 @@ const FibonacciDpWithoutRecursion = (number) => {
// Using Matrix exponentiation to find n-th fibonacci in O(log n) time
const copyMatrix = (A) => {
return A.map(row => row.map(cell => cell));
return A.map(row => row.map(cell => cell))
}
const Identity = (size) => {
const I = Array(size).fill(null).map(() => Array(size).fill());
const I = Array(size).fill(null).map(() => Array(size).fill())
return I.map((row, rowIdx) => row.map((_col, colIdx) => {
return rowIdx === colIdx ? 1 : 0
}))
@ -90,12 +90,12 @@ const matrixMultiply = (A, B) => {
const l = A.length
const m = B.length
const n = B[0].length // Assuming non-empty matrices
const C = Array(l).fill(null).map(() => Array(n).fill());
for(let i = 0; i < l; i++) {
for(let j = 0; j < n; j++) {
const C = Array(l).fill(null).map(() => Array(n).fill())
for (let i = 0; i < l; i++) {
for (let j = 0; j < n; j++) {
C[i][j] = 0
for(let k = 0; k < m; k++) {
C[i][j] += A[i][k]*B[k][j]
for (let k = 0; k < m; k++) {
C[i][j] += A[i][k] * B[k][j]
}
}
}
@ -105,15 +105,15 @@ const matrixMultiply = (A, B) => {
// A is a square matrix
const matrixExpo = (A, n) => {
A = copyMatrix(A)
if(n == 0) return Identity(A.length) // Identity matrix
if(n == 1) return A
if (n === 0) return Identity(A.length) // Identity matrix
if (n === 1) return A
// Just like Binary exponentiation mentioned in ./BinaryExponentiationIterative.js
let result = Identity(A.length)
while(n > 0) {
if(n%2 !== 0) result = matrixMultiply(result, A)
n = Math.floor(n/2)
if(n > 0) A = matrixMultiply(A, A)
while (n > 0) {
if (n % 2 !== 0) result = matrixMultiply(result, A)
n = Math.floor(n / 2)
if (n > 0) A = matrixMultiply(A, A)
}
return result
}
@ -121,7 +121,7 @@ const matrixExpo = (A, n) => {
const FibonacciMatrixExpo = (n) => {
// F(0) = 0, F(1) = 1
// F(n) = F(n-1) + F(n-2)
// Consider below matrix multiplication:
// Consider below matrix multiplication:
// | F(n) | |1 1| |F(n-1)|
// | | = | | * | |
@ -129,17 +129,17 @@ const FibonacciMatrixExpo = (n) => {
// F(n, n-1) = pow(A, n-1) * F(1, 0)
if(n === 0) return 0;
if (n === 0) return 0
const A = [
[1, 1],
[1, 0]
]
const poweredA = matrixExpo(A, n-1) // A raise to the power n
[1, 1],
[1, 0]
]
const poweredA = matrixExpo(A, n - 1) // A raise to the power n
let F = [
[1],
[0]
]
[1],
[0]
]
F = matrixMultiply(poweredA, F)
return F[0][0]
}