Seemed straightforward and I got through the greedy logic fine.
Start by clarifying edge cases like empty string, single word longer than W, and multiple spaces. Then describe a greedy algorithm that iterates through words, maintaining the current line length and incrementing the line count when adding the next word would exceed W. Finally, discuss time and space complexity and potential optimizations.
Pro tip: Mention that you would handle the case where a single word exceeds W by either truncating or allowing it to overflow, and ask the interviewer which behavior they prefer. This shows attention to detail and real-world constraints.
Ask about empty input, words longer than W, multiple spaces, and whether trailing spaces count. Confirm that words are separated by single spaces.
Explain that you'll iterate through words, keeping track of current line length. If adding a word (plus a space if not first) exceeds W, start a new line and increment line count.
Use a small example like W=10 and 'hello world foo bar' to demonstrate how the algorithm works step by step, showing line breaks and final count.
State that time complexity is O(n) where n is number of words, and space is O(1) extra. Mention that you could avoid splitting the string by scanning characters, but splitting is simpler.
Implement the function with clear variable names, handle edge cases, and mentally test with examples including empty string and single long word.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.
Model the problem as minimizing the maximum of two functions f(w1) and g(W-w1), where f and g represent the number of lines each paragraph takes given a width. Use binary search on the answer (the maximum number of lines) or ternary search on w1 to find the optimal split, leveraging the monotonicity of line counts with respect to width.
Pro tip: Mention that the line count function is a step function (non-increasing as width increases), so the maximum of the two is unimodal or can be handled with binary search on the answer, and discuss edge cases like very narrow or very wide columns.
Let L1(w) be the number of lines paragraph 1 takes at width w, and L2(w) similarly. We want to minimize max(L1(w1), L2(W-w1)) over w1 in [0, W].
L1(w) is non-increasing as w increases (wider column → fewer lines), and L2(W-w1) is non-decreasing as w1 increases. Thus the maximum of the two is minimized where they cross or at the boundary.
Use binary search on the answer: for a candidate max lines M, check if there exists w1 such that L1(w1) ≤ M and L2(W-w1) ≤ M. Alternatively, ternary search on w1 if the function is unimodal.
For a given M, find the range of widths where L1(w) ≤ M (i.e., w ≥ w1_min) and where L2(W-w) ≤ M (i.e., w ≤ w1_max). If w1_min ≤ w1_max, then M is feasible.
Since widths are likely integers (pixels or characters), binary search over integer w1 or over M. Precompute line counts for all possible widths to make checks O(1).
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.