带矢量对象C ++的Quicksort函数 [英] Quicksort function with vector object C++
问题描述
我正在尝试将此函数转换为使用矢量对象而不是整数数组.向量对象如下所示:
I'm trying to convert this function to use a vector object instead of an integer array. The vector object looks like this:
std::vector<Heltal *> htal;
Heltal类包含一个名为heltal的私有整数.
The Heltal class contains a private integer named heltal.
如何使用下面的函数对htal向量进行排序?
How would I sort the htal vector using the function below?
void Array::Sort(int a[], int first, int last)
{
int low = first;
int high = last;
int x = a[(first+last)/2];
do {
while(a[low] < x) {
low++;
}
while(a[high] > x) {
high--;
}
if(low<=high) {
std::swap(a[low],a[high]);
low++;
high--;
}
} while(low <= high);
if(first < high)
Array::Sort(a,first,high);
if(low < last)
Array::Sort(a,low,last);
}
推荐答案
The correct solution is to ditch your custom sort and use std::sort
from <algorithm>
. This will pretty much be guaranteed to be faster and more optimal in almost every case. Then you just have:
#include <algorithm>
...
std::vector<Heltal *> htal;
...
// sort by pointer value
std::sort(htal.begin(), htal.end());
如果要按对象值而不是指针值排序,请使用 std :: vector< Heltal>
而不是 std :: vector< Heltal *>
(几乎肯定是您应该做的事情),或者将比较函数传递给std :: sort.
If you want to sort by object value rather than pointer value, either use std::vector<Heltal>
instead of std::vector<Heltal *>
(which is almost certainly what you should be doing anyway), or pass a comparison function to std::sort.
为此使用C ++ 11 lambda的示例:
Example using C++11 lambda for this:
std::sort(htal.begin(), htal.end(), [](Heltal *a, Heltal *b) { return *a < *b; });
这篇关于带矢量对象C ++的Quicksort函数的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!