View difference between Paste ID: 3dfGADWc and itJ7E5BA

 /*
 Given a positive integer n, find the smallest integer which has exactly the same digits existing in the integer n and is greater in value than n. If no such positive integer exists, return -1.
 
 Input format
 A 32 bit integer N
 
 Output format
 A single integer
 
 Sample Input 1
 12
 
 Sample Output 1
 21
 
 Explanation
 There is only one number greater than 12 which is composed of 2 and 1 and it is 21.
 
 Constraints
 0<= N <= 10^9
 */
 
 vector<int> getDigits(int n) {
     vector<int> digits;
     while (n > 0) {
         digits.push_back(n % 10);
         n /= 10;
     }
     reverse(digits.begin(), digits.end());
     return digits;
 }
 
 /**
  * @param {number} n
  * @return {number}
  */
 // https://www.youtube.com/watch?v=LuLCLgMElus ; TUF
 function nextGreaterElementWithSameSetOfDigits(n) {
      let arr=getDigits(n);
      let length=arr.length;
      if(length<=1)
      return -1;
      let index1,index2;
      let i=length-2,j;
      while(i>=0&&arr[i]>=arr[i+1]){
          i--;
      }
      index1=i;
      if(index1>=0){
          i=length-1;
         while(i>=0&&arr[i]<=arr[index1]){
             i--;
         }
         index2=i;
         [arr[index1],arr[index2]]=[arr[index2],arr[index1]];
      }
      else
      return -1;
 
      // reverse after index1+1;
      i=index1+1;
      j=length-1;
      while(i<j){
          [arr[i],arr[j]]=[arr[j],arr[i]];
          i++;
          j--;
      }
      return parseInt(arr.join(''));
 
 
 }
 /*
 function nextGreaterElementWithSameSetOfDigits(n) {
     let arr=getDigits(n);
     // console.log(arr);// order  of digit should be inPlace
     let i,j;
     let length=arr.length;
     let hasFound=false;
     if(n<10)
     return -1;
     for(let i=length-1;i>=0;i--){
         for(let j=i-1;j>=0;j--){
             if(arr[i]>arr[j]){
                 [arr[i],arr[j]]=[arr[j],arr[i]];
                 hasFound=true;
                 break;
             }
         }
         if(hasFound)
             break;
     }
     if(!hasFound)
     return -1;
     return parseInt(arr.join(''));
 }
 */
 
 function main() {
     const n = parseInt(readLine(), 10);
     console.log(nextGreaterElementWithSameSetOfDigits(n));
 }