问使用多个线程的快速排序使最后的1/6未排序。

EN

# 1000000
314
267
213
934

#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <time.h>
#define BUF_SIZE 1024

int sum; /* this data will be shared by the thread(s) */
int * bigArr;
int size;
int findMedian(int array[], int size)
{
    if (size % 2 != 0)
        return array[size / 2];

    return (array[(size - 1) / 2] + array[size / 2]) / 2;
}
/*compare function for quicksort*/
int _comp(const void* a, const void* b) {
    return ( *(int*)a - *(int*)b);
}

/*This function is the problem method*/
/*indicate range of array to be processed with the index(params)*/
void *threadFct(int param)
{
    int x= size/6;
    if(param==0)x= size/6;
    if(param>0&&param<5)x= (size/6)*param;
    if(param==5)x= (size/6)*param+ (size%size/6);/*pass remainder into last thread*/
    qsort((void*)bigArr, x, sizeof(bigArr[param]), _comp);
    pthread_exit(0);
}

int main(int argc, char *argv[])
{
    FILE *source;
    int i =0;

    char buffer[BUF_SIZE];

    if(argc!=2){
        printf("Error. please enter ./a followed by the file name");
        return -1;}

    source= fopen(argv[1], "r");
    if (source == NULL) { /*reading error msg*/
        printf("Error. File not found.");
        return 1;
    }
    int count= 0;
    while (!feof (source)) {
        if (fgets(buffer, sizeof (buffer), source)) {
            if(count==0){  /*Convert string to int using atoi*/
                char str[1];
                sprintf(str, "%c%c%c%c%c%c%c%c%c",buffer[2],buffer[3],buffer[4],buffer[5],buffer[6],buffer[7],buffer[8],buffer[9],buffer[10]);/*get string of first */
                size= atoi(str); /* read the size of file--> FIRST LINE of file*/
                printf("SIZE: %d\n",size);
                bigArr= malloc(size*sizeof(int));
            }
            else{
                //printf("[%d]= %s\n",count-1, buffer); /*reads in the rest of the file*/
                bigArr[count-1]= atoi(buffer);
            }
            count++;
        }
    }

/*thread the unsorted array*/
    pthread_t tid[6]; /* the thread identifier */
    pthread_attr_t attr; /* set of thread attributes */

// qsort((void*)bigArr, size, sizeof(bigArr[0]), _comp);  <---- sorts array without threading
    for(i=0; i<6;i++){
        pthread_create(&tid[i], NULL, &threadFct, i);
        pthread_join(tid[i], NULL);
    }

    printf("Sorted array:\n");

    for(i=0; i<size;i++){
        printf("%i \n",bigArr[i]);
    }

    fclose(source);
}