Java > Array-2 > twoTwo (CodingBat Solution)

Problem:

Given an array of ints, return true if every 2 that appears in the array is next to another 2.

twoTwo({4, 2, 2, 3}) → true
twoTwo({2, 2, 4}) → true
twoTwo({2, 2, 4, 2}) → false


Solution:

public boolean twoTwo(int[] nums) {
  boolean isTrue = false;
  
  for (int i = 0; i < nums.length; i++) {
    if (nums[i] == 2) {
      if (nums.length > 1 && i < nums.length-1 && nums[i+1] == 2)
        isTrue = true;
      else if (nums.length > 1 && i > 0 && nums[i-1] == 2)
        isTrue = true;
      else
        return false;
    }  
  }
  return true;
}

7 comments:

  1. lakohotJune 20, 2019 at 6:43 AM

    public boolean twoTwo(int[] nums) {
    int[] nums1 = new int[nums.length + 2];

    for (int i = 0; i < nums.length; i++) {
    nums1[i+1] = nums[i];
    }

    for (int i = 0; i < nums1.length ; i++) {
    if (nums1[i] == 2) {
    if (!(nums1[i+1] == 2 || nums1[i-1] == 2)) return false;
    }


    }
    return true;
    }

    ReplyDelete
  2. AnarAghaNovember 8, 2020 at 7:22 AM

    A little bit long but works))

    public static boolean twoTwo(int[] nums) {
    boolean twice = true;
    if(nums.length>1 && nums[0]==2 && nums[1]!=2){
    return false;
    }
    if(nums.length>1 && nums[nums.length-1]==2 && nums[nums.length-2]!=2){
    return false;
    }
    for(int i=1; i<nums.length-1; i++){
    if(nums[i]==2){
    if(nums[i-1]!=2 && nums[i+1]!=2){
    twice = false;
    }
    }

    }
    return twice;

    }

    ReplyDelete
    Replies
    1. ambanielphasMarch 28, 2022 at 11:55 PM

      //added if array length is 1 with value 2
      public boolean twoTwo(int[] nums) {
      boolean twice = true;

      if(nums.length==1 && nums[0]==2){
      return false;
      }

      if(nums.length>1 && nums[0]==2 && nums[1]!=2){
      return false;
      }

      if(nums.length>1 && nums[nums.length-1]==2 && nums[nums.length-2]!=2){
      return false;
      }

      for(int i=1; i<nums.length-1; i++){
      if(nums[i]==2){
      if(nums[i-1]!=2 && nums[i+1]!=2){
      twice = false;
      }
      }
      }

      return twice;
      }

      Delete
  3. Mohamed KarmFebruary 6, 2021 at 3:44 AM

    public boolean twoTwo(int[] nums) {
    int count=0;//دا بيعد كل اتنين ورا بعض بواحد
    int count2=0;//دا بيعد عدد الاتنين في الاراي
    for(int i=0;i<nums.length;i++){
    if(nums[i]==2)count2++;
    if(i<nums.length-1 && nums[i]==2&&nums[i+1]==2){count++;
    }

    }
    return(count2==count*2 || count2==3&&count==2);//حاله خاصه اللى بعد ال or
    }

    ReplyDelete
  4. ambanielphasMarch 28, 2022 at 11:55 PM

    public boolean twoTwo(int[] nums) {
    boolean twice = true;

    if(nums.length==1 && nums[0]==2){
    return false;
    }

    if(nums.length>1 && nums[0]==2 && nums[1]!=2){
    return false;
    }

    if(nums.length>1 && nums[nums.length-1]==2 && nums[nums.length-2]!=2){
    return false;
    }

    for(int i=1; i<nums.length-1; i++){
    if(nums[i]==2){
    if(nums[i-1]!=2 && nums[i+1]!=2){
    twice = false;
    }
    }
    }

    return twice;
    }

    ReplyDelete
  5. AnonymousSeptember 20, 2023 at 9:27 PM

    public boolean twoTwo(int[] nums) {

    int count=0;

    for(int i=0; i0 && nums[i-1]==2) || (i=0 && count%2==0);
    }

    ReplyDelete
  6. AnonymousSeptember 20, 2023 at 9:35 PM


    public boolean twoTwo (int[]nums)
    {
    int count = 0;

    for (int i = 0; i < nums.length; i++)
    {
    if (nums[i] == 2)
    {
    if ((i > 0 && nums[i - 1] == 2)
    || (i < nums.length - 1 && nums[i + 1] == 2))
    {
    count += 2;
    i++;
    }
    else
    {
    count = count - 1;
    }
    }
    }
    return (count >= 0 && count % 2 == 0);
    }

    ReplyDelete