六种常见的排序方法

#include "iostream"
#include "vector"
#include "iterator"
#include "ctime"
#include "random"

template<typename T>
inline void Swap(T & a, T & b){  //交换变量
	T tmp = a;
	a = b;
	b = tmp;
}

template<typename T>
inline bool cmp(const T & a, const T & b){  //比较函数
	return a <= b;
}

template<typename T>
void Select_sort(std::vector<T> & v){    //选择排序
	for (unsigned i = 0; i < v.size() - 1; ++i){
		int best = i;
		for (unsigned j = i + 1; j < v.size(); ++j)
            if (cmp(v[j], v[best]))
                best = j;
		Swap(v[i], v[best]);
	}
}

template<typename T>
void Bubble_sort(std::vector<T> & v){    //冒泡排序
	for (unsigned i = 0; i < v.size() - 1; ++i){
		bool exchange = false;
		for (unsigned j = v.size() - 1; j > i; --j)
            if (cmp(v[j], v[j - 1])){
                Swap(v[j], v[j - 1]);
                exchange = true;
            }
		if (!exchange) return;
	}
}

template<typename T>
void Insertion_sort(std::vector<T> & v){     //插入排序
	for (int i = 1, j; i < v.size(); ++i){
		T key = v[i];
		for (j = i - 1; j >= 0; --j){
			if (cmp(key, v[j])) v[j + 1] = v[j];
			else break;
		}
		v[j + 1] = key;
	}
}

template<typename T>
void Shell_sort(std::vector<T> & v){     //希尔排序
	for(int gap = v.size()/2; gap > 0; gap /= 2)
		for(int i = gap; i < v.size(); ++i)
			for(int j = i - gap; j >= 0 && cmp(v[j + gap], v[j]); j -= gap)
				Swap(v[j], v[j + gap]);
}

template<typename T>
void Merge_sort(std::vector<T> & v, std::vector<T> & t, int x, int y){    //归并排序
	if (y - x <= 1) return;
	int m = x + (y - x) / 2;
	int p = x, q = m, i = x;
	Merge_sort(v, t, x, m);
	Merge_sort(v, t, m, y);
	while (p < m || q < y){
		if (q >= y || (p < m && cmp(v[p], v[q]))) t[i++] = v[p++];
		else t[i++] = v[q++];
	}
	std::copy(t.begin() + x, t.begin() + y, v.begin() + x);
}

template<typename T>
void Quick_sort(std::vector<T> & v, int x, int y){    //快速排序
	if (y <= x) return;
	int i = x, j = y, m = v[i];
	while (i < j){
		while (i < j && cmp(m, v[j])) --j;
		if (i < j) v[i++] = v[j];
		while (i < j && cmp(v[i], m)) ++i;
		if (i < j) v[j--] = v[i];
	}
	v[i] = m;
	Quick_sort(v, x, i - 1);
	Quick_sort(v, i + 1, y);
}

int main(int argc, char const *argv[])
{
	std::vector<int> v;
	srand(time(NULL));
	for(int i = 0; i < 102400; ++i)
        v.push_back(rand());
	std::vector<int> T(v.size());
	clock_t start_time = clock();
	//Select_sort(v);                     //3931MS
	//Bubble_sort(v);                     //22230MS
	//Insertion_sort(v);                  //1809MS
	//Shell_sort(v);                      //31MS
	//Merge_sort(v, T, 0, v.size());      //15MS
	//Quick_sort(v, 0, v.size()-1);       //15MS
	clock_t end_time = clock();
	std::cout << "Running Time:" << (double)(end_time - start_time) / CLOCKS_PER_SEC * 1000 << "MS" << std::endl;
	//std::copy(v.begin(), v.end(), std::ostream_iterator<int>(std::cout, "
"));  //输出
	return 0;
}