Small challenges.
Stronger problem solving.
352 programming exercises and projects, from interview patterns to practical data automation.
25 problems
01Repair an empty-input crashPython · Read errors before changing codeEasyFree02Repair a missing-field crashPython · Read errors before changing codeEasyFree03Repair division by zeroPython · Read errors before changing codeEasyFree04Minimize a wrong-match reproductionPython · Build a minimal reproductionEasyFree05Reduce a quantifier bugPython · Build a minimal reproductionEasyFree06Separate prefix from containmentPython · Build a minimal reproductionMediumPractice pack07Repair an inclusive endpointPython · Find boundary and off-by-one errorsMediumPractice pack08Retain a short final chunkPython · Find boundary and off-by-one errorsMediumPractice pack09Include the final adjacent pairPython · Find boundary and off-by-one errorsMediumPractice pack10Repair unexpected input mutationPython · Trace mutation and aliasingMediumPractice pack11Repair a shallow-copy leakPython · Trace mutation and aliasingMediumPractice pack12Preserve valid falsy valuesPython · Distinguish missing from falsyMediumPractice pack13Define the empty averagePython · Distinguish missing from falsyMediumPractice pack14Report absent fields preciselyPython · Distinguish missing from falsyMediumPractice pack15Reject booleans and partial numeric textPython · Inspect coercion and comparison rulesMediumPractice pack16Repair lexical numeric sortingPython · Inspect coercion and comparison rulesMediumPractice pack17Repair stale run statePython · Keep a regression for every repairMediumPractice pack18Repair deletion while iteratingPython · Keep a regression for every repairMediumPractice pack19Make a tie rule deterministicPython · Make results deterministicMediumPractice pack20Make grouped output stablePython · Make results deterministicMediumPractice pack21Review an almost-correct interval helperPython · Review plausible generated codeMediumPractice pack22Review an unstated winner policyPython · Review plausible generated codeMediumPractice pack23Review unequal-length assumptionsPython · Review plausible generated codeMediumPractice pack24Design tests for exact text semanticsPython · Design assertions that distinguish wrong implementationsMediumPractice pack25Design a duplicate-sensitive assertionPython · Design assertions that distinguish wrong implementationsMediumPractice pack
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