Trying to solve the Counting Bits using JavaScript ,basically finding the number of set bits for all numbers from 0 to N and push them in an array and return as answer
Here is explanation
Input: n = 5
Output: [0,1,1,2,1,2]
Explanation:
0 --> 0
1 --> 1
2 --> 10
3 --> 11
4 --> 100
5 --> 101
Here is the solution in Javascript
const countBits = function (nums){
let mem = [];
mem[0] = 0;
for (let i=0;i<=nums;i++)
mem[i] = mem[i/2] + i%2;
return mem;
}
i see output as
PS C:\VSB-PRO> node Fibo.js
[ 0, NaN, NaN, NaN, NaN ]
Here is the reference code trying to convert which was previously written in Java
class Solution {
public:
vector<int> countBits(int num) {
//mem[i] = No of 1s from 0 to number i
vector<int> mem(num+1);
mem[0] = 0;
for(int i=1;i<=num;++i)
mem[i] = mem[i/2] + i%2;
return mem;
}
};
Your help is very much appreciated
Regards,
Carolyn
The thing is that in Java / represents integer division when the operands are integers, but in JavaScript, the division will be a floating point division, so that 1/2 == 0.5, and then mem[0.5] will be an undefined value.
Use the bit shift operator instead to get the same behaviour:
const countBits = function(nums) {
let mem = [0];
for (let i = 0; i <= nums; i++)
mem[i] = mem[i >> 1] + i % 2;
return mem;
}
console.log(countBits(5));Converting positive numbers to a Javascript string object will work for you
console.log(Number(256).toString(2)); // 100000000If your array contains both positive and negative numbers, then you can use the "unsigned right shift" operator with toString method again.
console.log((-256 >>> 0).toString(2)); // 11111111111111111111111100000000