------
## 最终结论
```python
import itertools

def overlap(s1, s2):
    max_overlap = 0
    for i in range(1, min(len(s1), len(s2)) + 1):
        if s1[-i:] == s2[:i]:
            max_overlap = i
    return max_overlap

def find_shortest_superstring(A):
    # Generate all permutations of the input array A
    permutations = itertools.permutations(A)
    
    # Initialize shortest superstring
    shortest_superstring = None
    
    # Iterate over each permutation
    for perm in permutations:
        superstring = perm[0]
        
        # Build the superstring by adding each string with maximum overlap
        for i in range(1, len(perm)):
            current_overlap = overlap(superstring, perm[i])
            superstring += perm[i][current_overlap:]
        
        # Update the shortest superstring found
        if shortest_superstring is None or len(superstring) < len(shortest_superstring):
            shortest_superstring = superstring
    
    # Return the shortest superstring found
    return shortest_superstring

# Example usage:
print(find_shortest_superstring(["alex","loves","leetcode"]))  # Output: "alexlovesleetcode"
print(find_shortest_superstring(["catg","ctaagt","gcta","ttca","atgcatc"]))  # Output: "gctaagttcatgcatc"
```