Text Justification

Pack words greedily: starting at index i, include as many words as fit when at least one separating space is counted between adjacent words. For a completed nonfinal line, let chars be the sum of word lengths and spaces=maxWidth-chars. If there is one word, append all spaces after it. Otherwise each gap gets spaces/gaps, and the first spaces%gaps gaps get one extra space, which creates the required left bias. The final line is different: join its words with single spaces and pad the remaining width on the right. Advance i to the first unconsumed word and repeat. Every word is processed once and output construction is proportional to output size, so time is O(total characters) with line-sized working state. Check an exactly fitting line, a single long permitted word, and last-line padding. State why greedily maximizing words is safe: later words cannot make the current line better justified.