A. Check if Every Row and Column Contains All Numbers (opens new window)

Check the number of unique numbers on each row and column.

DETAILS

def checkValid(self, A: List[List[int]]) -> bool:
        return all(len(set(a)) == len(A) for a in A) and all(len(set(a)) == len(A) for a in zip(*A))

2134. Minimum Swaps to Group All 1's Together II (opens new window)

Sliding window.

DETAILS

def minSwaps(self, A: List[int]) -> int:
        n = len(A)
        num_one = sum(A)
        num_zero = n - sum(A)
        
        curr = sum(A[:num_one])
        ans = num_one - curr
        
        for i in range(num_one, n):
            curr += A[i]
            curr -= A[i - num_one]
            
            ans = min(ans, num_one - curr)
            
        curr = sum(A[:num_zero])
        ans = min(ans, curr)
        
        for i in range(num_zero, n):
            curr += A[i]
            curr -= A[i - num_zero]
            
            ans = min(ans, curr)
            
        return ans

C. Count Words Obtained After Adding a Letter (opens new window)

Rearrange every word from S into sorted anagram, for example: rumble -> belmru.
Take a word t from T, remove one character from it and check if its sorted anagram appears in S.

DETAILS

def wordCount(self, S: List[str], T: List[str]) -> int:
        S = set(["".join(sorted(list(s))) for s in S])
        ans = 0
        
        for t in T:
            cur_t = list(t)
            for i in range(len(cur_t)):
                tmp = cur_t[:i] + cur_t[i + 1:]
                if "".join(sorted(tmp)) in S:
                    ans += 1
                    break            

        return ans

D. Earliest Possible Day of Full Bloom (opens new window)

Plant the flower with shortest plantTime.

DETAILS

def earliestFullBloom(self, P: List[int], G: List[int]) -> int:
        res = 0
        for grow, plant in sorted(zip(G, P)):
            res = max(res, grow) + plant
        return res