Python - Algorithm #45

Python Algorithm

LeetCode

3270. Find the Key of the Numbers

• You are given three positive integers num1, num2, and num3.
• The key of num1, num2, and num3 is defined as a four-digit number such that:
  • Initially, if any number has less than four digits, it is padded with leading zeros.
  • The iᵗʰ digit (1 ≤ i ≤ 4) of the key is generated by taking the smallest digit among the iᵗʰ digits of num1, num2, and num3.
• Return the key of the three numbers without leading zeros (if any).
• Constraints
  • 1 ≤ num1, num2, num3 ≤ 9999

class Solution:
    def generateKey(self, num1: int, num2: int, num3: int) -> int:
        # zip
        str_1 = str(num1).zfill(4)
        str_2 = str(num2).zfill(4)
        str_3 = str(num3).zfill(4)
        answer = ""
        for chr_1, chr_2, chr_3 in zip(str_1, str_2, str_3):
            answer += min(chr_1, chr_2, chr_3)
        return int(answer)

class Solution:
    def generateKey(self, num1: int, num2: int, num3: int) -> int:
        str1 = str(num1).zfill(4)
        str2 = str(num2).zfill(4)
        str3 = str(num3).zfill(4)
        answer = ""
        for i in range(4):
            answer += min(str1[i], str2[i], str3[i])
        return int(answer)

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1572. Matrix Diagonal Sum

• Given a square matrix [mat], return the sum of the matrix diagonals.
• Only include the sum of all the elements on the primary diagonal and all the elements on the secondary diagonal that are not part of the primary diagonal.
• Constraints
  
  • n == mat.length == mat[i].length
  • 1 ≤ n ≤ 100
  • 1 ≤ mat[i][j] ≤ 100

class Solution:
    def diagonalSum(self, mat: List[List[int]]) -> int:
        answer = 0
        n = len(mat)
        for i in range(n):
            answer += mat[i][i]
            answer += mat[i][n-1-i]
        # 한 변의 길이가 홀수일 때는 겹치는 중간값 한번 빼주기
        if n % 2 == 1:
            answer -= mat[n//2][n//2]
        return answer

class Solution:
    def diagonalSum(self, mat: List[List[int]]) -> int:
        n = len(mat)
        answer = 0
        for i in range(n):
            answer += (mat[i][i] + mat[i][-i-1])
        if n % 2 != 0:
            answer -= mat[n//2][n//2]
        return answer

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https://leetcode.com/problems/find-the-key-of-the-numbers/

https://leetcode.com/problems/matrix-diagonal-sum/