Single customer
The matrix has one row. The sum of that row is the answer — no comparison needed.
Sum each row. Keep the maximum.
A private bank ranks clients by total holdings spread across multiple accounts. Each row of the ledger represents one client; each column a different account. The teller sums every row and tracks the running maximum — the wealthiest client's total emerges after a single pass over the matrix. O(m × n) time. O(1) extra space.
Watch row sums accumulate
Row = Customer, Sum = Wealth
Each row of the matrix represents one customer's portfolio. The column index identifies which bank holds that balance. Summing across a row gives total wealth for that customer. The richest customer is the one whose row sum is largest.
Two nested loops
A nested loop sums each customer's balances, keeping track of the running maximum. Every cell is visited exactly once.
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1
Initialize maximum
Set
richest = 0. No customer has been evaluated yet. -
2
Sum each row
For each customer (row), compute the sum of all bank balances in that row.
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3
Track maximum
If the current row sum exceeds
richest, update it. After all rows,richestholds the answer.
Edge patterns
Understanding boundary behavior is as important as the main algorithm path.
Single bank
Each customer has one account. The problem reduces to finding the maximum element.