Question

我无法让我的runner.c看到我的mergesort.h导入，这是我在进行评论之前需要做的最后一件事。

没有看到我在这里做错了所以我想我会更多的目光来看待它。我在这里查了一些问题，并且几乎复制了我实验室教授的模板，但它仍然不起作用。

错误

/tmp/ccf8TT1E.o: In function `main':
/home/carson/CProgs/lab5/runner.c:10: undefined reference to `mergeSort'
/home/carson/CProgs/lab5/runner.c:11: undefined reference to `print'
collect2: error: ld returned 1 exit status

runner.c

#include <stdio.h>
#include <stdlib.h>
#include "mergesort.h"

int main()
{
    int length = 4;
    int array[4] = {7,5,3,1};

    mergeSort(array, length);
    print(array,length);
}

mergesort.h

#ifndef MERGESORT_H_
#define MERGESORT_H_

void mergeSort(int* x, int length);

#endif

mergesort.c

#include <stdio.h>
#include <stdlib.h>
#include "mergesort.h"

void mergeSort(int* array, int length)
{
    if(length == 2)
    {
        if(array[1] < array[0])
        {
            swap(&array[1],&array[0]);
        }
        return;
    }
    else if(length == 1)
    {
        return;
    }
    else
    {
        if(length%2 == 0)
        {

            int halfLength = length/2;
            int bottomHalf[halfLength];
            int topHalf[halfLength];

            int i;
            for(i = 0; i <= (halfLength); i++)
            {
                bottomHalf[i] = array[i];
                topHalf[i] = array[i+(halfLength)];
            }

            mergeSort(bottomHalf, halfLength);
            mergeSort(topHalf, halfLength);

            int arrayLoc = 0;
            int bottomHalfLoc = 0;
            int topHalfLoc = 0;
            while(bottomHalfLoc < halfLength && topHalfLoc < halfLength)
            {
                if(bottomHalf[bottomHalfLoc] > topHalf[topHalfLoc])
                {
                    array[arrayLoc] = topHalf[topHalfLoc];
                    topHalfLoc++;
                }
                else
                {
                    array[arrayLoc] = bottomHalf[bottomHalfLoc];
                    bottomHalfLoc++;
                }

                arrayLoc++;
            }

            if(bottomHalfLoc < arrayLoc)
            {
                while(bottomHalfLoc < halfLength)
                {
                    array[arrayLoc] = bottomHalf[bottomHalfLoc];
                    bottomHalfLoc++;
                    arrayLoc++;
                }
            }

            return;
        }else 
        {
            int halfLength = length/2;
            int bottomHalf[halfLength];
            int topHalf[halfLength+1];

            int i;
            for(i = 0; i <= (halfLength); i++)
            {
                bottomHalf[i] = array[i];
            }

            for(i = 0; i <=(halfLength+1); i++)
            {
                topHalf[i] = array[i+halfLength];
            }

            mergeSort(bottomHalf, halfLength);
            mergeSort(topHalf, halfLength);

            int arrayLoc = 0;
            int bottomHalfLoc = 0;
            int topHalfLoc = 0;
            while(bottomHalfLoc < halfLength && topHalfLoc < halfLength)
            {
                if(bottomHalf[bottomHalfLoc] > topHalf[topHalfLoc])
                {
                    array[arrayLoc] = topHalf[topHalfLoc];
                    topHalfLoc++;
                }
                else
                {
                    array[arrayLoc] = bottomHalf[bottomHalfLoc];
                    bottomHalfLoc++;
                }

                arrayLoc++;
            }

            if(bottomHalfLoc < arrayLoc)
            {
                while(bottomHalfLoc < halfLength)
                {
                    array[arrayLoc] = bottomHalf[bottomHalfLoc];
                    bottomHalfLoc++;
                    arrayLoc++;
                }
            }
        return;
        }
    }
}

void swap(int *smallerValue, int *largerValue)
{
    int temp = *smallerValue;
    *smallerValue = *largerValue;
    *largerValue = temp;
}


void print(int array[], int length)
{
    printf("%d",array[0]); 
    int i;
    for(i = 1; i < length; i++)
    {
        printf(",%d",array[i]);
    }

    printf("\n");
}

Answer 1

使用gcc *.c -o runner.out还有一件事我没有看到mergesort.h文件中的print函数，但是你在main函数中调用它。包含它或使用extern print(array,length);

C头文件不起作用？

1 个答案: