垂直三角波绘制代码求助：修改振幅致图案错乱

Hey there! Let's dig into why adjusting the amplitude is breaking your vertical triangle wave. The issue almost certainly comes from hardcoded values tied to the original amplitude of 5 in your drawWave function—when you change the amplitude, those fixed values don't scale with it, leading to misaligned rows and messed-up symmetry.

Common Causes of the Problem #

Here are the most likely issues in your original code:

• You're using a fixed number of rows (like 9, which is 2*5-1) instead of calculating rows based on the input amplitude.
• The spacing or star count calculations rely on the constant 5 instead of the passed amplitude parameter.
• The rise/fall phases of the triangle aren't scaled dynamically with the amplitude.

Corrected Code Example #

Let's rewrite the functions to use the amplitude parameter everywhere, so the wave scales correctly no matter what value you pass:

#include <iostream>
using namespace std;

// Draws a single line of the vertical triangle wave
void drawWaveLine(int amplitude, int currentRow) {
    int spaces, stars;

    // Rise phase: from bottom (or top) to peak
    if (currentRow < amplitude) {
        spaces = amplitude - currentRow - 1;
        stars = currentRow * 2 + 1;
    }
    // Fall phase: from peak back down
    else {
        spaces = currentRow - amplitude + 1;
        stars = (2 * amplitude - 1) - (currentRow - amplitude + 1) * 2;
    }

    // Print leading spaces
    for (int i = 0; i < spaces; ++i) {
        cout << " ";
    }
    // Print the wave segment
    for (int i = 0; i < stars; ++i) {
        cout << "*";
    }
    cout << endl;
}

// Draws one full period of the vertical triangle wave
void drawOnePeriod(int amplitude) {
    // Total rows in one period: 2*amplitude - 1 (rise takes amplitude rows, fall takes amplitude-1)
    const int totalRows = 2 * amplitude - 1;
    for (int row = 0; row < totalRows; ++row) {
        drawWaveLine(amplitude, row);
    }
}

int main() {
    int userAmplitude;
    cout << "Enter amplitude value: ";
    cin >> userAmplitude;
    drawOnePeriod(userAmplitude);
    return 0;
}

How This Works #

• Dynamic Row Calculation: totalRows is computed as 2*amplitude -1—this ensures the wave has the right height for any amplitude (e.g., amplitude 3 gives 5 rows, amplitude 4 gives 7 rows).
• Scaled Spacing & Stars: For each row, we calculate spaces and stars based on whether we're in the rise or fall phase, using the input amplitude instead of a fixed 5. This keeps the wave symmetric at any size.
• Flexible Amplitude: You can now pass any positive integer to drawOnePeriod (e.g., drawOnePeriod(3) or drawOnePeriod(7)) and get a clean, correctly shaped vertical triangle wave.

Quick Check for Your Original Code #

If you want to fix your existing code instead of rewriting, look for these fixes:

• Replace every hardcoded 5 in drawWave with the amplitude parameter passed to it.
• Update the loop in drawOnePeriod to run for 2*amplitude -1 rows instead of a fixed number.
• Verify that the rise phase runs for amplitude rows and the fall phase runs for amplitude-1 rows.

内容的提问来源于stack exchange，提问作者Ahmed Mahmoud