The problem is asking to implement a string decoding system. The rules of the system are as follows:

1. If a digit 'n' is encountered, it means that the substring enclosed in square brackets '[' and ']' should be repeated 'n' times.
2. If a pair of square brackets is encountered without a preceding digit, the enclosed substring should be repeated once.

Here is a Python solution for the problem:

```python
def decode_string(s):
stack = []
stack.append(["", 1])
num = ""
for ch in s:
if ch.isdigit():
num += ch
elif ch == '[':
stack.append(["", int(num)])
num = ""
elif ch == ']':
st, k = stack.pop()
stack[-1][0] += st*k
else:
stack[-1][0] += ch
return stack[0][0]
```

This function uses a stack to keep track of the substrings and their repeat counts. When a digit is encountered, it is added to the current number string. When an opening bracket is encountered, a new element is pushed onto the stack with the current number as the repeat count and an empty string as the substring. When a closing bracket is encountered, the top element is popped from the stack, and its substring is repeated according to its repeat count and appended to the substring of the new top element of the stack. When a character is encountered, it is appended to the substring of the top element of the stack. Finally, the function returns the substring of the initial element on the stack, which contains the decoded string.

Question

The problem is asking to implement a string decoding system. The rules of the system are as follows:

1. If a digit 'n' is encountered, it means that the substring enclosed in square brackets '[' and ']' should be repeated 'n' times.
2. If a pair of square brackets is encountered without a preceding digit, the enclosed substring should be repeated once.

Here is a Python solution for the problem:

```python
def decode_string(s):
    stack = []
    stack.append(["", 1])
    num = ""
    for ch in s:
        if ch.isdigit():
            num += ch
        elif ch == '[':
            stack.append(["", int(num)])
            num = ""
        elif ch == ']':
            st, k = stack.pop()
            stack[-1][0] += st*k
        else:
            stack[-1][0] += ch
    return stack[0][0]
```

This function uses a stack to keep track of the substrings and their repeat counts. When a digit is encountered, it is added to the current number string. When an opening bracket is encountered, a new element is pushed onto the stack with the current number as the repeat count and an empty string as the substring. When a closing bracket is encountered, the top element is popped from the stack, and its substring is repeated according to its repeat count and appended to the substring of the new top element of the stack. When a character is encountered, it is appended to the substring of the top element of the stack. Finally, the function returns the substring of the initial element on the stack, which contains the decoded string.

Knowee AI · Accepted Answer

The problem is asking to implement a string decoding system. The rules of the system are as follows:

1. If a digit 'n' is encountered, it means that the substring enclosed in square brackets '[' and ']' should be repeated 'n' times.
2. If a pair of square brackets is encountered without a preceding digit, the enclosed substring should be repeated once.

Here is a Python solution for the problem:

```python
def decode_string(s):
    stack = []
    stack.append(["", 1])
    num = ""
    for ch in s:
        if ch.isdigit():
            num += ch
        elif ch == '[':
            stack.append(["", int(num)])
            num = ""
        elif ch == ']':
            st, k = stack.pop()
            stack[-1][0] += st*k
        else:
            stack[-1][0] += ch
    return stack[0][0]
```

This function uses a stack to keep track of the substrings and their repeat counts. When a digit is encountered, it is added to the current number string. When an opening bracket is encountered, a new element is pushed onto the stack with the current number as the repeat count and an empty string as the substring. When a closing bracket is encountered, the top element is popped from the stack, and its substring is repeated according to its repeat count and appended to the substring of the new top element of the stack. When a character is encountered, it is appended to the substring of the top element of the stack. Finally, the function returns the substring of the initial element on the stack, which contains the decoded string.

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