Question

求C语言快速排序程序

求C语言快速排序程序代码(最好有注释)

Answer 1

#include <stdio.h>

int partions(int l[],int low,int high)
{
int prvotkey=l[low];
l[0]=l[low];
while (low<high)
{
while (low<high&&l[high]>=prvotkey)
--high;
l[low]=l[high];
while (low<high&&l[low]<=prvotkey)
++low;
l[high]=l[low];
}

l[low]=l[0];
return low;
}

void qsort(int l[],int low,int high)
{
int prvotloc;
if(low<high)
{
prvotloc=partions(l,low,high); //将第一次排序的结果作为枢轴
qsort(l,low,prvotloc-1); //递归调用排序 由low 到prvotloc-1
qsort(l,prvotloc+1,high); //递归调用排序 由 prvotloc+1到 high

}
}

void quicksort(int l[],int n)
{
qsort(l,1,n); //第一个作为枢轴 ，从第一个排到第n个
}

void main()
{
int a[11]={0,2,32,43,23,45,36,57,14,27,39};

for (int b=1;b<11;b++)
printf("%3d",a[b]);

printf("\n");
quicksort(a,11);

for(int c=1;c<11;c++)
printf("%3d",a[c]);

}

Answer 2

#include <iostream>

using namespace std;

void quicksort(int n[], int left, int right);
int partition(int n[], int left, int right);

int main()
{
int as[5] = {23, 43, 13, 56, 68};
quicksort(as, 0, 5);
for(int i = 0; i != 5; i++)
{
cout << as[i] << ' ';
}
}

void quicksort(int n[], int left, int right)
{
int dp;
if (left < right)
{
dp = partition(n, left, right);
quicksort(n, left, dp - 1);
quicksort(n, dp + 1, right);
}
}

int partition(int n[], int left, int right)
{
int lo,hi,pivot,t;

pivot = n[left];
lo = left - 1;
hi = right + 1;

while(lo+1 != hi)
{
if(n[lo + 1] <= pivot)
lo++;
else if(n[hi - 1] > pivot)
hi--;
else
{
t = n[lo + 1];
n[++lo] = n[hi - 1];
n[--hi] = t;
}
}
n[left] = n[lo];
n[lo] = pivot;
return lo;
}

//解释你在网上搜，很容易找到

Answer 3

冒泡排序就挺快的

Answer 4

#include<stdio.h>
void quicksort(int a[],int low,int high)
{
int t,i,j;
i=low;
j=high;
if(low<high)
{
t=a[low];
while(i!=j)
{
while(a[j]>t&&i<j)j--;
if(i<j)
{
a[i]=a[j];
i++;
}
while(a[i]<t&&i<j)i++;
if(i<j)
{
a[j]=a[i];
j--;
}
}
a[i]=t;
quicksort(a,low,i-1);
quicksort(a,i+1,high);
}
}
void main()
{
int i,a[20001],n;
while(scanf("%d",&n)!=EOF)
{
for(i=1;i<=n;i++)
scanf("%d",&a[i]);
quicksort(a,1,n);
for(i=1;i<=n;i++)
{
if(i!=n)printf("%d ",a[i]);
else printf("%d\n",a[i]);
}
}
return 0;
}