[Leet Code] Running Sum of 1D Array

Problem : https://leetcode.com/problems/running-sum-of-1d-array/

Running Sum of 1d Array - LeetCode

 

My solution :

class Solution:
    def runningSum(self, A):
        ans = [A[0]] * len(A)
        
        for idx in range(1, len(A)): 
            ans[idx] = ans[idx - 1] + A[idx] 
            
        return ans

 

Submission Result :

 

Lesson :

1. 1D array와 2D array 크기 지정 방법이 서로 다름 

# 1D Array 
list_1d = ['A'] * 10
print(list_1d)

# Output
['A', 'A', 'A', 'A', 'A', 'A', 'A', 'A', 'A', 'A']



# 2D Array
list_2d = [['A'] * 10 for _ in range(2)]
print(list_2d)

# Output
[['A', 'A', 'A'], ['A', 'A', 'A']]

 

2. 이번에는 방망이 깎는 노인처럼 코드 라인 수를 줄여보았다 

# Before:
ans = [None] * len(A)
ans[0] = A[0]

# After:
ans = [A[0]] * len(A)