Help me in solving DNASTORAGE problem

help
,
1

My issue

For encoding an even-length binary string into a sequence of A, T, C, and G, we iterate from left to right and replace the characters as follows:

00 is replaced with A
01 is replaced with T
10 is replaced with C
11 is replaced with G
Given a binary string
�
S of length
�
N (
�
N is even), find the encoded sequence.

Input Format
First line will contain
�
T, number of test cases. Then the test cases follow.
Each test case contains two lines of input.
First line contains a single integer
�
N, the length of the sequence.
Second line contains binary string
�
S of length
�
N.
Output Format
For each test case, output in a single line the encoded sequence.

Note: Output is case-sensitive.

Constraints
1
≤
�
≤
100
1≤T≤100
2
≤
�
≤
1
0
3
2≤N≤10
3

�
N is even.
Sum of
�
N over all test cases is at most
1
0
3
10
3
.
�
S contains only characters 0 and 1.
Sample 1:
Input
Output
4
2
00
4
0011
6
101010
4
1001
A
AG
CCC
CT
Explanation:
Test case
1
1: Based on the rules 00 is replaced with A.

Test case
2
2: Based on the rules 00 is replaced with A. Similarly, 11 is replaced with G. Thus, the encoded sequence is AG.

Test case
3
3: The first two characters are 10 which is encoded as C. Similarly, the next two characters 10 are encoded as C and the last two characters 10 are encoded as C. Thus, the encoded string is CCC.

Test case
4
4: The first two characters are 10 which is encoded as C. Similarly, the next two characters 01 are encoded as T. Thus, the encoded string is CT.

My code

# cook your dish here

Learning course: Strings using Python
Problem Link: CodeChef: Practical coding for everyone

2

@kumari18
plzz refer the following code for better understanding of the logic and implementation.

# cook your dish here
n=int(input())
for i in range(1,n+1):
    a=int(input())
    z=""
    h=str(input())
    for j in range(0,a,2):
        if(h[j]+h[j+1]=="00"):
            z=z+"A"
        elif(h[j]+h[j+1]=="01"):
            z=z+"T"
        elif(h[j]+h[j+1]=="10"):
            z=z+"C"
        else:
            z=z+"G"
    print(z)