JS exercises

Transform from a decimal number system to binary one

const decimalToBinary = decimalNumber => {
// Your code
}

console.assert(decimalToBinary(5) === "101");
console.assert(decimalToBinary(798) === "1100011110");

Soluction

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Transform from a binary number system to decimal one

const binaryToDecimal = binaryNumber => {
// Your code
}

console.assert(binaryToDecimal("101") === 5);
console.assert(binaryToDecimal("1100011110") === 798);

Soluction

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Summarize two binary numbers

const summarizeBinaries = (x, y) => {
// Your code
}

console.assert(
  summarizeBinaries("101", "11101") === "100010"
);
console.assert(
  summarizeBinaries("1100011110", "10101010101") === "100001110011"
);

Soluction

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Substruct two binary numbers

const substructBinaries = (x, y) => {
// Your code
}

Soluction

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Create a bit vector (each item has 32 bits)

const createBitVector = amountOfbites => {
  // Your code
  return {
    turnOn: index => {},
    turnOff: index => {},
    toggle: index => {},
    get: index => {},
  }
}


const bitVector = createBitVector(34);

bitVector.turnOn(0);
bitVector.get(0); // 1

bitVector.turnOff(0);
bitVector.get(0); // 0

bitVector.turnOn(33);
bitVector.toggle(32);
bitVector.get(32); // 1
bitVector.toggle(32);
bitVector.get(32); // 0
bitVector.get(33); // 1

bitVector.turnOn(34); // Error: Index must be bigger than 0 and less than 34

Soluction

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Splice a chunk of a donor binary to main one. Need to select bits from 0 to n of donorBinary and insert into mainBinary from start to end. n is difference between start and end (inclusively).

const spliceBinary = (mainBinary, donorBinary, start, end) => {
  // Your code
}

/*
1. Selected first 4 bits of donorBinary (0b1101).
2. Insert into mainBinary from 3 to 6.
*/
spliceBinary(0b0, 0b1101, 3, 6).toString(2) //-> "1101000"

spliceBinary(0b10100100111101100, 0b111010, 3, 9).toString(2) //-> "10100100111010100"
spliceBinary(0b1111111111, 0b0, 2, 5).toString(2) //-> "1111000011"

Soluction

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Write a function that determines the number of bits that can be changed in order to get b from number a.

const determineBits = (a, b) => {
  // Your code
};

determineBits(0b11, 0b0); //-> 2
determineBits(0b1001, 0b101); //-> 2
determineBits(0b11111, 0b10111); //-> 1
determineBits(0b1, 0b1); //-> 0

Soluction

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Write an algorithm that changes the even bits to odd ones. Loops cannot be used (for, while, etc.)

const swapBits = value => {
  // Your code
};

swapBits(0b101010).toString(2); //-> "10101"
swapBits(0b10101).toString(2); //-> "1010"

Soluction

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Write a stack with limited size.

const createStack = size => {
  // Your code
}

const stack = createStack(3);
stack.push(1);
stack.push(2);
stack.push(3);
stack.peek(); //-> 3
stack.pop(); //-> 3
stack.peek(); //-> 2

stack.push(4);
stack.push(5); //-> Error: Stack overflow

Soluction

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Define a helper function that gets one class and extends it with two others

const applyMixins (derivedCtor, baseCtors) => {
  // Your code
}
//The parent classes
class A {

    methodA(){
        console.log("A")
    }
}

class B {

    methodB(){
        console.log("B")
    }
}

//The child class
class C {

}

//Using mixins
applyMixins(C, [A, B])
let o = new C()
o.methodA() //-> 'A'
o.methodB() //-> 'B'

Soluction

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