保龄球计分循环代码调试求助：isNinetySix测试用例结果不符

It sounds like you're hitting a common snag with bowling score logic—off-by-a-few-points errors usually boil down to mishandling strikes, spares, or the 10th frame's special rules. Let's break down how to debug this:

First, Let's Pin Down the Likely Issues #

Since you're getting 98 instead of the expected 96, your code is overcounting by 2 points. Here are the most probable culprits:

1. Incorrect Spare/Strike Bonus Calculation #

• Spares: If your code is adding two subsequent rolls instead of one for a spare, that could add an extra 2 points (e.g., if the next roll is a 2).
• Strikes: If you're not stopping bonus calculations after the 10th frame, you might be counting the extra 10th-frame rolls twice (once as part of the strike bonus, once as a new frame).

2. Flawed String Parsing #

Your rolls method cuts off at if (s..., so let's verify how you're handling characters:

• For a strike (X): Are you storing only one 10 in the rolls array, and incrementing roll by 1? If you're incorrectly storing 10 and 0 (and incrementing by 2), this shifts all subsequent rolls and breaks bonus math.
• For a spare (/): Are you calculating the second roll as 10 - previousDigit (e.g., 7/ becomes 7 and 3)? Storing 10 directly for the / would overcount the frame.
• For a gutter ball (-): Are you storing 0 instead of skipping the entry?

3. Not Limiting Calculations to 10 Frames #

If your score calculation loop runs through the entire rolls array (21 entries) instead of stopping after 10 frames, you'll count the extra 10th-frame rolls (for strikes/spares) as an 11th frame. For example, if those extra rolls sum to 2, that's exactly your overcount.

Example Fix for Score Calculation #

Here's a standard, correct score calculation method to compare against your code:

public int calculateScore() {
    int totalScore = 0;
    int currentRoll = 0;
    
    for (int frame = 0; frame < 10; frame++) {
        // Handle strike
        if (rolls[currentRoll] == 10) {
            totalScore += 10 + rolls[currentRoll + 1] + rolls[currentRoll + 2];
            currentRoll++; // Strike only uses one roll
        } 
        // Handle spare
        else if (rolls[currentRoll] + rolls[currentRoll + 1] == 10) {
            totalScore += 10 + rolls[currentRoll + 2];
            currentRoll += 2; // Spare uses two rolls
        } 
        // Open frame
        else {
            totalScore += rolls[currentRoll] + rolls[currentRoll + 1];
            currentRoll += 2;
        }
    }
    return totalScore;
}

Debugging Steps to Confirm #

1. Log the rolls array: Print out the values stored after parsing your test case's scorecard. Compare them to a manual parse of the same string—this will catch parsing errors immediately.
2. Step through the score calculation: Manually compute the score frame by frame, then walk through your code's logic to see where it deviates. Look for the frame where the total jumps by an extra 2 points.
3. Verify the 10th frame: If your test case includes a strike or spare in the 10th frame, ensure the extra rolls are only counted as part of the 10th frame's bonus, not as a new frame.

内容的提问来源于stack exchange，提问作者Jon309