Question

Digit pairs
given n three-digit numbers

Answer 1

Answer:

Consider following examples:

Say, number is 286

Largest digit is 8 and smallest digit is 2

So, 8.11+2.7 =102 so ignore most significant bit , So bit score = 02.

Say, Number is 123

Largest digit is 3 and smallest digit is 1

Largest digit is 3 and smallest digit is 1

So, 3.11+7, =40, so bit score is 40

Rules for making pairs from above calculated bit scores  

Condition for making pairs are

• Both bit scores should be in either odd position or even position to be eligible to form a pair.

• Pairs can be only made if most significant digit are same and at most two pair can be made for a given significant digit.

- Constraints  

N<=500

- Input Format  

First line contains an inter N, denoting the count of numbers.

Second line contains N 3-digit integers delimited by space

- Output  

One integer value denoting the number of bit pairs.

— Test Case  

- Explanation  

Example 1

Input

8234567321345123110767111

Output  

3

Explanation

After getting the most and least significant digits of the numbers and applying the formula given in Rule 1 we get the bit scores of the numbers as:

5812407640111918

No. of pair possible are 3:

40 appears twice at odd-indices 3 and 5 respectively.

Hence, this is one pair. 12, 11, 18 are at even-indices.

Hence, two pairs are possible from these three-bit scores.

Hence total pairs possible is 3

Explanation: