Understand how to identify and generate the k-th lucky number, which consists only of digits 4 and 7, by applying bitwise manipulation techniques. This lesson helps you practice problem-solving skills relevant for coding interviews and teaches the logic behind efficient solution development.
Statement
A number is called lucky if it comprises only the digits 4 and 7. Your task is to return the k-th lucky number as a string for a given integer k.
Constraints:
1<=k<=109
Examples
1/ 3
Understand the problem
Let’s take a moment to make sure you’ve correctly understood the problem. The quiz below helps you check if you’re solving the correct problem:
Find The K-th Lucky Number
1.
What digits are considered lucky?
A.
3 and 8
B.
2 and 5
C.
4 and 7
D.
6 and 9
1 / 3
Figure it out!
We have a game for you to play. Rearrange the logical building blocks to develop a clearer understanding on how to solve this problem.
Sequence - Vertical
Drag and drop the cards to rearrange them in the correct sequence.
1
2
3
4
5
Try it yourself
Implement your solution in the following coding playground.
Understand how to identify and generate the k-th lucky number, which consists only of digits 4 and 7, by applying bitwise manipulation techniques. This lesson helps you practice problem-solving skills relevant for coding interviews and teaches the logic behind efficient solution development.
Statement
A number is called lucky if it comprises only the digits 4 and 7. Your task is to return the k-th lucky number as a string for a given integer k.
Constraints:
1<=k<=109
Examples
1/ 3
Understand the problem
Let’s take a moment to make sure you’ve correctly understood the problem. The quiz below helps you check if you’re solving the correct problem:
Find The K-th Lucky Number
1.
What digits are considered lucky?
A.
3 and 8
B.
2 and 5
C.
4 and 7
D.
6 and 9
1 / 3
Figure it out!
We have a game for you to play. Rearrange the logical building blocks to develop a clearer understanding on how to solve this problem.
Sequence - Vertical
Drag and drop the cards to rearrange them in the correct sequence.
1
2
3
4
5
Try it yourself
Implement your solution in the following coding playground.