C语言中将0-10范围直方图修改为-5到5范围的技术求助

Hey there! I see you’ve been stuck adjusting your histogram from a 0-10 range to -5 to 5—let’s work through this together. The core issue here is that when you subtract 5 from your original 0-10 values, you end up with negative numbers, but array indices can’t be negative. We just need a small offset to map those negative values to valid positions in your histogram array.

Here are the exact changes you need to make:

1. Update the Histogram Creation (tworz_histogram) #

Right now, you’re directly using the array’s 0-10 values as histogram indices. We first subtract 5 to shift values into the -5 to 5 range, then add 5 again to convert those negative/zero/positive values into valid 0-10 indices for the histogram array:

void tworz_histogram() // Now handles -5 to 5 range
{
    int i;
    czysc_histogram();
    for(i=0; i<TABLE_SIZE; i++)
    {
        int adjusted_value = tablica[i] - 5; // Convert original 0-10 to -5 to 5
        histogram[adjusted_value + 5]++; // Shift to valid 0-10 index (-5+5=0, 5+5=10)
    }
}

2. Update the Histogram Display (wyswietl_histogram) #

Your current code prints 0-10 as the value labels, but we need to show -5 to 5 instead. Just subtract 5 from the loop index i to get the correct label for each histogram bin:

void wyswietl_histogram() // Print histogram with -5 to 5 labels
{
    int i;
    for(i=0; i<HISTOGRAM_SIZE; i++)
    {
        printf("Liczba %d: %d\n", i - 5, histogram[i]); // i ranges 0-10, so i-5 is -5 to 5
    }
}

Full Modified Code #

Here’s the complete code with these changes applied:

#include<stdio.h>
#include<stdlib.h>
#include<time.h>
#include<math.h>
#define TABLE_SIZE 30
#define HISTOGRAM_SIZE 11 // Still 11 values (-5 to 5 inclusive)
int tablica[TABLE_SIZE];
int histogram[HISTOGRAM_SIZE];

void wylosuj_tablice() //generate an array
{
    int i;
    srand(time(0));
    for(i=0;i<TABLE_SIZE;i++)
    {
        tablica[i]=(rand()%HISTOGRAM_SIZE); // Still generates 0-10, we adjust later
    }
}

void czysc_histogram() //clean histogram
{
    int i;
    for(i=0; i<HISTOGRAM_SIZE; i++)
    {
        histogram[i] = 0;
    }
}

void tworz_histogram() // Now handles -5 to 5 range
{
    int i;
    czysc_histogram();
    for(i=0; i<TABLE_SIZE; i++)
    {
        int adjusted_value = tablica[i] - 5; // Convert original 0-10 to -5 to5
        histogram[adjusted_value + 5]++; // Map to valid histogram index (0-10)
    }
}

void wyswietl_histogram() // Print histogram with -5 to5 labels
{
    int i;
    for(i=0; i<HISTOGRAM_SIZE; i++)
    {
        printf("Liczba %d: %d\n", i - 5, histogram[i]);
    }
}

void wyswietl_tablice() //Print the array (shows original 0-10 values)
{
    int i;
    for(i=0; i<TABLE_SIZE; i++)
    {
        printf ("tablica[%d]=%d\n", i, tablica[i]);
    }
}

int main()
{
    wylosuj_tablice();
    wyswietl_tablice();
    tworz_histogram();
    wyswietl_histogram();
    return 0;
}

Quick Explanation #

• We keep generating 0-10 values in wylosuj_tablice as you did before, then subtract 5 in tworz_histogram to get the desired -5 to 5 range.
• Adding 5 to the adjusted value fixes the negative index problem: -5 +5 =0, 0+5=5, 5+5=10—perfectly matching your existing histogram array size.
• When printing, we reverse the offset by subtracting 5 from the loop index to show the correct -5 to 5 labels.

This should give you exactly the histogram you need!

内容的提问来源于stack exchange，提问作者matxi