#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#define MAX_SIZE 100

我正试图根据点到原点的距离快速排序一个二维点数组,但我的代码在第一个点之后点击了aSeg fault
typedef struct point{
double x;
double y;
double dist;
    } point;

void sortpoints(point arr[], int low, int high);
void printpoints(point arr[], int n);

Sortpoints只是根据scanf的值排序Point structs数组的快速排序操作
void sortpoints(point arr[], int low, int high){
    int piv, i, j;
    piv = low;
    i = low;
    j = high;
    point box;
    if(low < high){
        while(i<j){
            while((arr[i].dist)<=(arr[piv].dist) && i<= high)
                i++;
            }
            while((arr[j].dist) > (arr[piv].dist) && j>= low)
                j--;
            }
            if(i<j){
                box = arr[i];
                arr[i] = arr[j];
                arr[j] = box;
            }
        box = arr[j];
        arr[j] = arr[piv];
        arr[piv] = box;
        sortpoints(arr, low, j-1);
        sortpoints(arr, j+1, high);

    }

Printpoints只是按点与原点的距离顺序打印点
    void printpoints(point arr[], int n){
        int i; for(i = 0; i <= n; i++){
                    printf("(%.2lf, %.2lf)\n", arr[i].x, arr[i].y);
                }
    }

用户在表单中输入点数和点数值(point.x,point.y)
int main(){

    point pointa;
    point pointarray[MAX_SIZE];
    int n=0;
    printf("how many points would you like to enter?\n");
    scanf("%d", &n);
    if(n<MAX_SIZE){
        int i;
        for(i=0; i<n ; i++){
            scanf("(%lf,%lf)", &pointa.x, &pointa.y);
            pointa.dist = sqrt(pointa.x*pointa.x + pointa.y*pointa.y);
            pointarray[i] = pointa;
        }
        sortpoints(pointarray, 0, n-1);
        printpoints(pointarray, n);}
    else{
        printf("sorry, not a valid array size\n");
    }



    return 0;
}

最佳答案

我有堆栈溢出。
您的程序调用函数sortpoints,并调用自身(sortpoints调用sortpoints)。但我看不出sortpoints必须停在哪里!
因此,j-1将变为空,arr[j]完全无效。

关于c - 段错误,但我不知道为什么,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/20506769/

10-09 02:26