C++

1/*
2 * Runtime: 12 ms, faster than 39.22% 
3 * Memory Usage: 8.1 MB, less than 60.83%
4 */
5class Solution {
6  public:
7    int maximumWealth(vector<vector<int>>& accounts) {
8      int max = -1;
9      for(int i=0; i<accounts.size(); ++i) {
10        int sum = 0;
11        for(int j=0; j<accounts[i].size(); ++j) {
12          sum += accounts[i][j];
13        }
14        max = sum > max ? sum : max;
15      }
16      return max;
17    }
18};

JavaScript

1/**
2 * Runtime: 80 ms, faster than 56.45% 
3 * Memory Usage: 38.7 MB, less than 35.23%
4 */
5var maximumWealth = function(accounts) {
6  let max = 0;
7  accounts.forEach((bank) => {
8    let sum = 0;
9    bank.forEach((money) => {
10      sum += money;
11    });
12    max = sum > max ? sum : max;
13  });
14
15  return max;
16};

Ruby

1# Runtime: 52 ms, faster than 74.77% 
2# Memory Usage: 209.8 MB, less than 96.73%
3def maximum_wealth(accounts)
4  max = 0
5
6  accounts.each do |bank|
7    sum = 0
8    bank.each do |money|
9      sum += money
10    end
11    max = sum > max ? sum : max
12  end
13
14  max
15end