[JS] Minimum Length Substrings

minLenSubString.js

// Solution |s|**2 + |t|
function containsSubstring(str, startIdx, endIdx, substrMap) {
  const substrMapCopy = {...substrMap};
  for(let i = startIdx; i <= endIdx; i++) {
    const char = str[i];
    if(substrMapCopy[char]) {
      substrMapCopy[char] -= 1;
      if(substrMapCopy[char] === 0) { 
        delete substrMapCopy[char];
        if(!Object.keys(substrMapCopy).length) return true;
      }
    }  
  };
  
  return false;  
}

function minLengthSubstring(s, t) {
  const mapT = {};
  t.split("").forEach(char => {
    if(mapT[char]) mapT[char] += 1;  
    else mapT[char] = 1;
  });
  
  let j = 0;
  let minLengthSubstring = Infinity;
  for(let i = 0; i < s.length; i++) {
    while(j < s.length && !containsSubstring(s, i, j, mapT)) {
      j++;
    } 
    console.log(j)
    if(j === s.length) break;
    const newLength = j - i + 1;
    if(newLength < minLengthSubstring) minLengthSubstring = newLength;
  };
  
  return minLengthSubstring === Infinity ? -1 : minLengthSubstring;
}



// solution |s| + |t|
function minLengthSubstring(s, t) {
  if(t.length > s.length) return -1;
  if(t === "") return 0;
  if(s === "") return -1;
  
  const mapT = {};
  t.split("").forEach(char => {
    if(mapT[char]) mapT[char] += 1;  
    else mapT[char] = 1;
  });

  let result = Infinity;
  let nOfFormed = 0;  
  let l = 0; 
  let r = 0; 
  while(r < s.length) { 
    if(mapT[s[r]] !== undefined) { 
      mapT[s[r]] -=1;
      if(mapT[s[r]] === 0) nOfFormed++;      
    }        
    
    while(nOfFormed === t.length) {          
      const size = r - l + 1;
      if(size < result) { 
        result = size;
        if(result === t.length) return result;
      }
      
      if(mapT[s[l]] !== undefined) {
        mapT[s[l]] += 1;
        if(mapT[s[l]] >= 1) nOfFormed--;
      }
      l++;      
    }
                        
    r++;
  }
  
  return result === Infinity ? -1 : result;
}


// --------------------------- test -----------------------------//
console.log(minLengthSubstring("dcbefebce", "fd")) // 5
console.log(minLengthSubstring("bfbeadbcbcbfeaaeefcddcccbbbfaaafdbebedddf", "cbccfafebccdccebdd")) // -1
console.log(minLengthSubstring("", "fd")) // -1
console.log(minLengthSubstring("dcbefebce", "")) // 0
console.log(minLengthSubstring("dcffd", "fd")) // 2
console.log(minLengthSubstring("dcffd", "fd")) // 2
console.log(minLengthSubstring("dcffd", "az")) // -1