[LeetCode]#1672. Richest Customer Wealth

Environment: Python 3.7

Key technique: for, max

You are given an m x n integer grid accounts where accounts[i][j] is the amount of money the i​​​​​​​​​​​th​​​​ customer has in the j​​​​​​​​​​​th​​​​ bank. Return the wealth that the richest customer has.

A customer’s wealth is the amount of money they have in all their bank accounts. The richest customer is the customer that has the maximum wealth.

Example 1:

Input: accounts = [[1,2,3],[3,2,1]]
Output: 6
Explanation:
1st customer has wealth = 1 + 2 + 3 = 6
2nd customer has wealth = 3 + 2 + 1 = 6
Both customers are considered the richest with a wealth of 6 each, so return 6.

Example 2:

Input: accounts = [[1,5],[7,3],[3,5]]
Output: 10
Explanation: 
1st customer has wealth = 6
2nd customer has wealth = 10 
3rd customer has wealth = 8
The 2nd customer is the richest with a wealth of 10.

Example 3:

Input: accounts = [[2,8,7],[7,1,3],[1,9,5]]
Output: 17

Analysis:

1. Sum list a, b, c
2. Find the largest one.

Solution:

class Solution:
    def maximumWealth(self, accounts):
        ans, curr= 0, 0
        for i in accounts:
            for j in i:
                curr+=j
            ans=max(ans,curr)
            curr=0
        return ans

Submissions:

Reference:

https://leetcode.com/problems/richest-customer-wealth/discuss/959863/Simple-Naive-Python-constant-space-O(1)