DAY 3_DSA challange for 45 days

 Day 3. DSA challange for 45 days 

March 18,2024

Leetcode and geeksforgeeks questions and solutions

begin with simple and straightforward problems to test my concepts.

problem 1 : https://www.geeksforgeeks.org/problems/largest-element-in-array4009/1

solution: 

class Solution {
    largest(arr, n) {
        // write your code here
        let max=0
        let i=0
        while(i<n){
            if(max<arr[i]){
                max=arr[i]
            }
            i++
        }
        return max
    }
}

problem 2: https://www.geeksforgeeks.org/problems/second-largest3735/1
solution: 
class Solution{
    print2largest(arr,n){
   let fMax=-1
  let sMax=-1
  for(let i=0;i<n;i++){
      if(fMax<arr[i]){
        sMax=fMax
        fMax=arr[i]
      }
    else{
      if(fMax>arr[i] && sMax<arr[i]){
        sMax=arr[i]
      }
    }
  }
  return sMax
    }
}

problem 3 : https://leetcode.com/problems/remove-duplicates-from-sorted-array/description/
solution: 
var removeDuplicates = function(nums) {
 let count=1
for(let i=0;i<nums.length-1;i++){
    if(nums[i]<nums[i+1]){
      nums[count]=nums[i+1]
      count++
    }
  }
  return count
 
};

problem 4 : https://leetcode.com/problems/running-sum-of-1d-array/
solution: 
var runningSum = function(nums) {
    let sum=0
    for(let i=0;i<nums.length;i++){
        sum+=nums[i]
        nums[i]=sum
    }
    return nums
};


problem 5: https://leetcode.com/problems/single-number/description/
solution: 
var singleNumber = function(nums) {
    let ans=0
    for(let i=0;i<nums.length;i++){
       ans=ans ^ nums[i]
    }
    return ans
};


problem 6: https://leetcode.com/problems/max-consecutive-ones/description/
solution: 
var findMaxConsecutiveOnes = function(nums) {
let count=0
  let max=0
  for(let i=0;i<nums.length;i++){
    if(nums[i]==1){
      count++
      if(max<count){
        max=count
      } 
    }
    else{
      count=0
    }
  }
 return max
};
problem 7 : https://leetcode.com/problems/missing-number/
solution: 
var missingNumber = function(nums) {
    let sum=0;
    let sum2=0
    for(let i=0;i<=nums.length;i++){
        sum+=i
    }
    for(let i=0;i<nums.length;i++){
        sum2+=nums[i]
    }
    let ans=sum-sum2
      return ans
};