FA-79895 / Typography line breaking / Member archive

Total-fit paragraph demerits: interword gap count · case 05

Every line measures one space too wide and breaks too early.

Member previewVariant 5 · 3 implementations · 8 checks per implementation

Case contract

Input [word widths, [space, stretch, shrink] per gap, line width, line penalty]. A line i..j has gaps=j-i-1. The last line has zero badness when not overfull. Other lines use ratio shortfall/(stretch*gaps) or /(shrink*gaps); zero stretch with slack or compression past shrink is infeasible; badness=min(10000, floor(100|r|^3+1/2)) and must be <=1000. Fitness 0 tight (r<-1/2), 1 decent (r<=1/2), 2 loose (r<=1), 3 very loose; last line decent. Demerits (lp+b)^2 plus 3000 when adjacent fitness classes differ by more than 1, starting from decent. Return [min total demerits, break list] (ties: first found) or ["infeasible"].

Why this case matters

Line breaking decides where paragraphs wrap on screen and in print; a wrong decision point shifts every following line.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
regression: interword gap count	`[12296, [3, 7]]`	`[12200, [4, 7]]`	Failed

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This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

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