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实现了选择排序, 插入排序, 冒泡排序, 快速排序, 改进后的快速排序, 以及两路合并排序.
通过随机函数随机生成100个数, 进行各种排序, 记录排序开始时间以及结束时间, 计算消耗的时间来比较算法的优略.
实现代码:
#include "iostream"
#include "cstdio"
#include "cstring"
#include "algorithm"
#include "queue"
#include "stack"
#include "cmath"
#include "utility"
#include "map"
#include "set"
#include "vector"
#include "list"
#include "string"
#include "cstdlib"
#include "ctime"
using namespace std;
typedef long long ll;
const int MOD = 1e9 + 7;
const int INF = 0x3f3f3f3f;
const int MAXN = 1005;
template <class T>
void SelectSort(T A[], int n)
{
int small;
for(int i = 0 ; i < n; ++i) {
small = i;
for(int j = i + 1; j < n; ++j)
if(A[j] < A[small]) small = j;
swap(A[i], A[small]);
}
}
template <class T>
void InsertSort(T A[], int n)
{
for(int i = 1; i < n; ++i) {
int j = i;
T tmp = A[j];
while(j > 0 && tmp < A[j - 1]) {
A[j] = A[j - 1];
j--;
}
A[j] = tmp;
}
}
template <class T>
void BubbleSort(T A[], int n)
{
int i = n - 1, j, last;
while(i > 0) {
last = 0;
for(int j = 0; j < i; ++j)
if(A[j + 1] < A[j]) {
swap(A[j], A[j + 1]);
last = j;
}
i = last;
}
}
template <class T>
void QSort(T A[], int left, int right)
{
int i, j;
if(left < right) {
i = left, j = right + 1;
do {
do i++; while(A[i] < A[left]);
do j--; while(A[j] > A[left]);
if(i < j) swap(A[i], A[j]);
}while(i < j);
swap(A[left], A[j]);
QSort(A, left, j - 1);
QSort(A, j + 1, right);
}
}
template <class T>
void QuickSort(T A[], int n)
{
QSort(A, 0, n - 1);
}
template <class T>
void MagicQSort(T A[], int left, int right)
{
int i, j;
if(right >= 9) {
if(left < right) {
i = left, j = right + 1;
do {
do i++; while(A[i] < A[left]);
do j--; while(A[j] > A[left]);
if(i < j) swap(A[i], A[j]);
}while(i < j);
swap(A[left], A[j]);
MagicQSort(A, left, j - 1);
MagicQSort(A, j + 1, right);
}
}
else {
InsertSort(A, right - left + 1);
return;
}
}
template <class T>
void MagicQuickSort(T A[], int n)
{
MagicQSort(A, 0, n - 1);
}
template <class T>
void Merge(T A[], int i1, int j1, int i2, int j2)
{
T *tmp = new T[j2 - i1 + 1];
int i = i1, j = i2, k = 0;
while(i <= j1 && j <= j2) {
if(A[i] <= A[j]) tmp[k++] = A[i++];
else tmp[k++] = A[j++];
}
while(i <= j1) tmp[k++] = A[i++];
while(j <= j2) tmp[k++] = A[j++];
for(int i = 0; i < k; ++i)
A[i1++] = tmp[i];
delete []tmp;
}
template <class T>
void MergeSort(T A[], int n)
{
int i1, j1, i2, j2, size = 1;
while(size < 1) {
i2 = i1 + size;
j1 = i2 - 1;
if(i2 + size - 1 > n - 1) j2 = n - 1;
else j2 = i2 + size - 1;
Merge(A, i1, j1, i2, j2);
i1 = j2 + 1;
}
size *= 2;
}
int main(int argc, char const *argv[])
{
clock_t start, finish;
srand(time(NULL));
int n = 100, i;
int *a = new int[n];
int *b = new int[n];
int *c = new int[n];
int *d = new int[n];
int *e = new int[n];
int *f = new int[n];
cout << "待排序序列为:" << endl;
for(int i = 0; i < n; ++i)
{
a[i] = rand()%91;
cout << a[i] << " ";
b[i] = a[i];
c[i] = a[i];
d[i] = a[i];
e[i] = a[i];
f[i] = a[i];
}
cout << endl;
start = clock();
SelectSort(a, n);
cout << "经过简单选择排序后的序列为:" << endl;
for(i = 0; i < n; ++i)
cout << a[i] << " ";
cout << endl;
finish = clock();
cout << "开始时间为:" << start << " " << "结束时间为:" << finish << " " << "持续时间为:" << (double)(finish - start)/ CLOCKS_PER_SEC << endl;
start = clock();
InsertSort(b, n);
cout << "经过直接插入排序后的序列为:" << endl;
for(i = 0; i < n; ++i)
cout << b[i] << " ";
cout << endl;
finish = clock();
cout << "开始时间为:" << start << " " << "结束时间为:" << finish << " " << "持续时间为:" << (double)(finish - start)/ CLOCKS_PER_SEC << endl;
start = clock();
BubbleSort(c, n);
cout << "经过冒泡排序后的序列为:" << endl;
for(i = 0; i < n; ++i)
cout << c[i] << " ";
cout << endl;
finish = clock();
cout << "开始时间为:" << start << " " << "结束时间为:" << finish << " " << "持续时间为:" << (double)(finish - start)/ CLOCKS_PER_SEC << endl;
start = clock();
QuickSort(d, n);
cout << "经过快速排序后的序列为:" << endl;
for(i = 0; i < n; i++)
cout << d[i] << " ";
cout << endl;
finish = clock();
cout << "开始时间为:" << start << " " << "结束时间为:" << finish << " " << "持续时间为:" << (double)(finish - start)/ CLOCKS_PER_SEC << endl;
start = clock();
MergeSort(e, n);
cout << "经过两路合并排序后的序列为:" << endl;
for(i = 0; i < n; i++)
cout << e[i] << " ";
cout << endl;
finish = clock();
cout << "开始时间为:" << start << " " << "结束时间为:" << finish << " " << "持续时间为:" << (double)(finish - start)/ CLOCKS_PER_SEC << endl;
start = clock();
MagicQuickSort(f, n);
cout << "经过改进后的快速排序后的序列为:" << endl;
for(i = 0; i < n; ++i)
cout << f[i] << " ";
cout << endl;
finish = clock();
cout << "开始时间为:" << start << " " << "结束时间为:" << finish << " " << "持续时间为:" << (double)(finish - start)/ CLOCKS_PER_SEC << endl;
return 0;
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原文地址：http://blog.csdn.net/gkhack/article/details/50333181
