Group a list of duplicate Objects without removing duplicate into a map-CodePudding

I have a list of objects in an array. Each object has an email.

The array could have duplicate emails and I want to keep them.

I want to give a number let's say 4 and it should split the emails into groups of 4 emails into a map where the key is like group-1 ... and the value 4 unique emails in each key in this case I will have a map of 5 keys

const emails = [
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password1',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password1',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password10',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password10',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password2',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password2',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password3',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password3',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password4',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password4',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password5',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password5',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password6',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password6',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password7',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password7',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password8',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password8',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password9',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password9',
    recovery: '[email protected]'
  }
]

//this is the code i came up with but it's working

const groupsMap = new Map()
let sequence = 0
let profilePrefix = 'none'
let pivotPrefix = 0
for (let index = 0; index < emails.length; index  ) {
  const currentEmail = emails[index]?.email
  const prevEmail = emails[index - 1]?.email
  if (prevEmail && currentEmail === prevEmail) {
    if (
      profilesMap.has(`${prefix}-${pivotPrefix}`) &&
      profilesMap.get(`${prefix}-${pivotPrefix}`).length < mailboxProfileNum &&
      profilesMap
        .get(`${prefix}-${pivotPrefix}`)
        .findIndex((email) => currentEmail === email.email) === -1
    ) {
      profilesMap.get(`${prefix}-${pivotPrefix}`).push(emails[index])
      if (
        profilesMap.get(`${prefix}-${pivotPrefix}`).length === mailboxProfileNum
      ) {
        pivotPrefix  
      }
    } else {
      if (pivotPrefix > 0) {
        const nextPivot = pivotPrefix  
        profilesMap.get(`${prefix}-${nextPivot}`).push(emails[index])
      }
      sequence  
      profilePrefix = `${prefix}-${sequence}`
      profilesMap.set(profilePrefix, [emails[index]])
    }
  } else {
    if (profilesMap.has(`${prefix}-${pivotPrefix}`)) {
      if (
        profilesMap.get(`${prefix}-${pivotPrefix}`).length < mailboxProfileNum
      ) {
        profilesMap.get(`${prefix}-${pivotPrefix}`).push(emails[index])
        if (
          profilesMap.get(`${prefix}-${pivotPrefix}`).length ===
          mailboxProfileNum
        ) {
          pivotPrefix  
        }
      } else {
        sequence  
        profilesMap.set(`${prefix}-${sequence}`, [emails[index]])
      }
    } else {
      sequence  
      pivotPrefix = sequence
      profilePrefix = `${prefix}-${pivotPrefix}`
      profilesMap.set(profilePrefix, [emails[index]])
    }
  }
}


Map(5) {
    'group-1' => [
      {
        userId: 'userid',
        email: '[email protected]',
        password: 'password1',
        recovery: '[email protected]'
      },
      {
        userId: 'userid',
        email: '[email protected]',
        password: 'password2',
        recovery: '[email protected]'
      },
      {
        userId: 'userid',
        email: '[email protected]',
        password: 'password3',
        recovery: '[email protected]'
      },
      {
        userId: 'userid',
        email: '[email protected]',
        password: 'password4',
        recovery: '[email protected]'
      }
    ],
    'group-2' => [
      {
        userId: 'userid',
        email: '[email protected]',
        password: 'password1',
        recovery: '[email protected]'
      },
      {
        userId: 'userid',
        email: '[email protected]',
        password: 'password2',
        recovery: '[email protected]'
      },
      {
        userId: 'userid',
        email: '[email protected]',
        password: 'password3',
        recovery: '[email protected]'
      },
      {
        userId: 'userid',
        email: '[email protected]',
        password: 'password4',
        recovery: '[email protected]'
      }
    ],
    ...
 }

CodePudding user response：

You can save the groups as "buckets", and find the next bucket to put the email in. If no buckets have available spots, create a new bucket with the email.

const emails=[{userId:'someuserid',email:'[email protected]',password:'password1',recovery:'[email protected]'},{userId:'someuserid',email:'[email protected]',password:'password1',recovery:'[email protected]'},{userId:'someuserid',email:'[email protected]',password:'password10',recovery:'[email protected]'},{userId:'someuserid',email:'[email protected]',password:'password10',recovery:'[email protected]'},{userId:'someuserid',email:'[email protected]',password:'password2',recovery:'[email protected]'},{userId:'someuserid',email:'[email protected]',password:'password2',recovery:'[email protected]'},{userId:'someuserid',email:'[email protected]',password:'password3',recovery:'[email protected]'},{userId:'someuserid',email:'[email protected]',password:'password3',recovery:'[email protected]'},{userId:'someuserid',email:'[email protected]',password:'password4',recovery:'[email protected]'},{userId:'someuserid',email:'[email protected]',password:'password4',recovery:'[email protected]'},{userId:'someuserid',email:'[email protected]',password:'password5',recovery:'[email protected]'},{userId:'someuserid',email:'[email protected]',password:'password5',recovery:'[email protected]'},{userId:'someuserid',email:'[email protected]',password:'password6',recovery:'[email protected]'},{userId:'someuserid',email:'[email protected]',password:'password6',recovery:'[email protected]'},{userId:'someuserid',email:'[email protected]',password:'password7',recovery:'[email protected]'},{userId:'someuserid',email:'[email protected]',password:'password7',recovery:'[email protected]'},{userId:'someuserid',email:'[email protected]',password:'password8',recovery:'[email protected]'},{userId:'someuserid',email:'[email protected]',password:'password8',recovery:'[email protected]'},{userId:'someuserid',email:'[email protected]',password:'password9',recovery:'[email protected]'},{userId:'someuserid',email:'[email protected]',password:'password9',recovery:'[email protected]'}]

const buckets = [];

const bucketSize = 4;

emails.forEach((e) => {
    const bucketIndex = buckets
      .map((b, i) => [b, i]) // zip with index
      .filter(([b]) => b.length < bucketSize) // buckets that aren't full
      .find(([b]) => b.every((u) => u.email !== e.email)); // bucket with available spot

    if (bucketIndex === undefined) buckets.push([e]); // create new bucket
    else buckets[bucketIndex[1]].push(e); // push to existing bucket by index
});

// zip with keys and create map
const map = new Map(buckets.map((b, i) => [`group-${i}`, b]));

// Just for display - Maps aren't displayed properly in the output yet
console.log(Object.fromEntries(Array.from(map)));

.as-console-wrapper { max-height: 100% !important }

CodePudding user response：

Not sure But if you want group of unique emails than this will give you 4 object with unique emails.

First I am filtering array with unique values of email and than using chunk function, that takes two parameter one the array and second the size of array.
The procedure of chunk function is as below, the only thing **missing here is key otherwise you are getting 4 email object of array in chunks.
Take an empty array to push array chuncks
check if we will have extra chunks or not;
if array length's moudle with chunk size is not equal to zero that we have to count the number of rounds
if array length's moudle with chunk size is zero than we just need to push array.splice(0,size) till the array size is not equals to zero
if we have rounds , than we just need to push array till the rounds are not complete once its compelete we just need to add extra to result by arra.push(0,extra);
In other words,push chunks in array till our array's length is not equal to extra and once array length is just as extra add remaining by arra.push(0,extra);

const emails = [{
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password1',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password1',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password10',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password10',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password2',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password2',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password3',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password3',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password4',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password4',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password5',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password5',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password6',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password6',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password7',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password7',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password8',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password8',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password9',
    recovery: '[email protected]'
  },
  {
    userId: 'someuserid',
    email: '[email protected]',
    password: 'password9',
    recovery: '[email protected]'
  }
];
let filterdResult = []; // to store unique email objects
// to filter emails object with unique email
let filterArray = emails.reduce((visitedEmailContainer, currentEmail) => {
  if (!visitedEmailContainer.includes(currentEmail.email)) {
    filterdResult.push(currentEmail);
    visitedEmailContainer.push(currentEmail.email);
    return visitedEmailContainer;
  }
  return visitedEmailContainer;
}, []);

function chunk(array, size) {
  /*
  - Take an empty array to push array chuncks
  - check if we will have extra chunks or not;
  - if array length's moudle with chunk size is not equal to zero that we have to count the number of rounds
  - if array length's moudle with chunk size is zero than we just need to push array.splice(0,size) till the array size is not equals to zero
  - if we have rounds , than we just need to push array till the rounds are not complete once its compelete we just need to add extra to result by arra.push(0,extra); 
  - In other words,push chunks in array till our array's length is not equal to extra and once array length is just as extra add remaining by arra.push(0,extra);
   */
  let result = [];
  let extra = array.length % size;
  if (extra == 0) {
    while (array.length !== 0) {
      result.push(array.splice(0, size));
    }
  } else if (extra) {
    while (array.length != extra) {
      result.push(array.splice(0, size));
    }
    result.push(array.splice(0, extra));
  }
  console.log(result);
  return result;
}
chunk(filterdResult, 4);