p4

#include<stdio.h>
#include<stdlib.h>
#include<time.h>
#define max 30000
#define ntimes 2000
void swap(int *a,int *b){
    int temp=*a;
    *a=*b;
    *b=temp;
}
int partition(int a[],int lb,int ub){
    int pivot=a[lb];
    int start=lb;
    int end=ub;
    while(start<end){
        while(a[start]<=pivot){
            start++;
        }
        while(a[end]>pivot){
            end--;
        }
        if(start<end){
            swap(&a[start],&a[end]);
        }
    }
    swap(&a[lb],&a[end]);
    return end;
}
void quicksort(int a[],int lb,int ub){
    if(lb<ub){
       int loc=partition(a,lb,ub);
        quicksort(a,lb,loc-1);
        quicksort(a,loc+1,ub);
    }
}
int main(){
    int a[max],k,i,n;
    double runtime=0;
    clock_t start,end;
    printf("enter the num of values");
    scanf("%d",&n);
    srand(time(NULL));
    for(i=0;i<n;i++){
        a[i]=rand();
    }
    start=clock();
    quicksort(a,0,n-1);
    end=clock();
    runtime=(double)(end-start)/CLOCKS_PER_SEC;
    printf("the elements are:");
    for(i=0;i<n;i++)
    {
        printf("%d\n",&a[i]);
    }
    printf("the runtime=%lf",runtime);
    return 0;
}