breakwords dynamic javascript implementation https://www.youtube.com/watch?v=WepWFGxiwRs

breakwords2.js

function StringBuffer() {
  this.__strings__ = [];
}

StringBuffer.prototype.append = function (str) {
  this.__strings__.push(str);
};

StringBuffer.prototype.toString = function () {
  return this.__strings__.join('');
};

function breakWord(stringToBreak, dictionary) {
  const matrix = [];
  const len = stringToBreak.length;

  for (let i = 0; i < stringToBreak.length; i++) {
    matrix[i] = new Array(stringToBreak.length);
  }

  for (let i = 0; i < matrix.length; i++) {
    for (let j = 0; j < matrix[i].length; j++) {
      matrix[i][j] = -1; // -1 indicates string between i to j cannot be split
    }
  }

  for (let l = 1; l <= len; l++) {
    for (let i = 0; i < (len - l) + 1; i++) {
      const j = i + (l - 1);
      const str = stringToBreak.substring(i, j + 1);
       // if string between i to j is in dictionary matrix[i][j] is true
      if (dictionary.has(str)) {
        matrix[i][j] = i;
        continue;
      }
       // find a k between i+1 to j such that matrix[i][k-1] && matrix[k][j] are both true
      for (let k = i + 1; k <= j; k++) {
        if (matrix[i][k - 1] !== -1 && matrix[k][j] !== -1) {
          matrix[i][j] = k;
          break;
        }
      }
    }
  }
  if (matrix[0][len - 1] === -1) {
    return null;
  }

  const buffer = new StringBuffer();
  let i = 0;
  const j = len - 1;
  while (i < j) {
    const k = matrix[i][j];
    if (i === k) {
       // console.log(stringToBreak.substring(i, j + 1));
      buffer.append(stringToBreak.substring(i, j + 1));
      break;
    }
  //  console.log(`${stringToBreak.substring(i, k)  } `);
    buffer.append(`${stringToBreak.substring(i, k)} `);
    i = k;
  }
  return buffer.toString();
}

const mySet = new Set();

mySet.add('a');
mySet.add('i');
mySet.add('am');
mySet.add('ace');
mySet.add('you');
mySet.add('code');
mySet.add('love');
mySet.add('to');

const inputString = 'codeiloveto';

const result = breakWord(inputString, mySet);

console.log(result);