DAY 2 .DSA challange for 45 days 

March 16,2024

Leetcode and geeksforgeeks questions and solutions

begin with simple and straightforward problems to test my concepts.

 

problem 6 : https://www.geeksforgeeks.org/problems/print-table0303/1

solution: 

class Solution {
  getTable(N) {
    //code here
    let bag=[]
    for(let i=1;i<=10;i++){
        bag.push(i*N)
    }
    return bag
  }
}

problem 7 : https://www.geeksforgeeks.org/problems/reversing-the-equation2205/1

solution: 
class Solution {
    reverseEqn(s) {
        //code here
 s=s.match(/[0-9]+|[\/\*\+\-]/g)
return s.reverse().join("")
}
}
problem 8 : https://leetcode.com/problems/add-digits/description/

solution: 
while (num >= 10) {
        let sum = 0;
        while (num > 0) {
            sum += num % 10;
            num = Math.floor(num / 10);
        }
        num = sum;
    }
    return num;
};

OR
var addDigits = function(num) {
   
   num=num.toString()

   while(num.length>1){
    let temp=num.split("").map(Number)
    const sum = temp.reduce((accumulator, currentValue) => accumulator + currentValue, 0);
    num=sum.toString()
   }
   return +num

};


problem 9 : https://www.geeksforgeeks.org/problems/sum-of-digit-is-pallindrome-or-not2751/1

solution: 

class Solution {
    isDigitSumPalindrome(n){
       //code here
       n=n.toString()
       let sum=0
       for(let i=0;i<n.length;i++){
           sum+=Number(n[i])
       }
       sum=sum.toString()
       for(let i=0;i<sum.length;i++){
           if(sum[i]!=sum[sum.length-1-i]){
               return 0
           }
       }
       return 1
    }
}

Today, I started learning recursion by starting with very basic concepts
to get the hang of it. 

1.power function

let n = 2;
let r = 4
function fun(n, r) {
  if (r == 0) {
    return 1;
  } else {
    return n * fun(n, r - 1);
  }
};

console.log(fun(n, r));

2.Binary Equivalent-Recursion

// let n=15
let n=128

let bag=[]
function binary(n){
  if(n==0){
    return bag.reverse()
  }
  else {
     bag.push(n%2)
    return  binary(Math.floor(n/2))    
  }
}
console.log(binary(n).join(" "))