各种排序算法的C实现(转载)

本文为转载自http://blog.chinaunix.net/u2/70445/showart_1926713.html

 

#include <stdio.h>#include <stdlib.h>void InsertSort(int *num);void print(int *num);void BinsertSort(int *num);void ShellSort(int *num, int n);void popo(int *num, int n);void swap(int *a, int *b);int Partition(int *num, int low, int high);void QuikSort(int *num, int low, int high);int SelectMinKey(int *num, int i, int n);void SelectSort(int *num, int n);void Merge(int *R,int low,int m,int high);void MergeSort(int R[],int low,int high);void main(){int num[] = {49, 38, 65, 97, 76, 13, 27, 52};char ch;printf("num为:");print(num);printf("请选择排序的方式：/n");printf("a:直接插入排序/n");printf("b:折半插入排序/n");printf("c:希尔排序/n");printf("d:冒泡排序/n");printf("e:快速排序/n");printf("f:简单选择排序/n");printf("g:2-路归并排序/n");printf("请选择：");ch = getchar();switch (ch){case 'a':printf("直接插入排序/n");InsertSort(num);break;case 'b':printf("折半插入排序/n");BinsertSort(num);break;case 'c':printf("希尔排序/n");ShellSort(num, 8);break;case 'd':printf("冒泡排序/n");popo(num, 8);break;case 'e':printf("快速排序/n");QuikSort(num, 0, 7);break;case 'f':printf("简单选择排序/n");SelectSort(num, 8);break;case 'g':printf("2-路归并排序/n");MergeSort(num, 0, 7);break;default:printf("wrong choice!/n");break;}print(num);}//直接插入排序void InsertSort(int *num){int i = 0, j = 0;int temp;for (i=1; i < 8; i++){temp = num[i];for (j=i-1; j>0; j--){if (num[j] < temp)break;num[j+1] = num[j];}num[j+1] = temp;}}//输出元素void print(int *num){for (int i = 0; i < 8; i++)printf("%d ", num[i]);printf("/n");}//折半插入排序void BinsertSort(int *num){int i, j;int low, high, mid;int temp;for (i = 1; i < 8; i++){temp = num[i];low = 0;high = i-1;while (low <= high){mid = (low+high)/2;if (num[mid] >= temp){low = mid + 1;} else{high = mid - 1;}}for (j = i; j > high+1; j--){num[j] = num[j-1];}num[high+1] = temp; }}//希尔排序 n为元素个数void ShellSort(int *num, int n){int dk = n/2; //增量int i = 0, j = 0;int temp;while (dk){for (i=dk; i<n; i++){for (j=i-dk; j>=0 && num[j] > num[j+dk]; j -= dk){temp = num[j];num[j] = num[j+dk];num[j+dk] = temp;}}dk /= 2;}}//冒泡排序void popo(int *num, int n){int i, j;for(i=1; i<=n; i++){for (j=0; j<n-i; j++){if (num[j] > num[j+1]){int temp = num[j];num[j] = num[j+1];num[j+1] = temp;}}}}//快速排序void swap(int *a, int *b){int temp = *a;*a = *b;*b = temp;}int Partition(int *num, int low, int high){int pivotkey = num[low];while (low < high){while (low<high && num[high] >= pivotkey)high--;swap(&num[low], &num[high]);while (low<high && num[low] <= pivotkey)low++;swap(&num[low], &num[high]);}return low;}void QuikSort(int *num, int low, int high){int pivotloc = 0; //枢轴的位置if (low<high){pivotloc = Partition(num, low, high); //将数组划分高低两部分QuikSort(num, low, pivotloc-1); //分别对高低表进行排序QuikSort(num, pivotloc+1, high);}}//简单选择排序int SelectMinKey(int *num, int i, int n) //在num[i]~num[n-1]中选出key最小的记录{int minkey = num[i];int pos;int minkeypos;for (pos = i; pos < n; pos++){if(minkey > num[pos]){minkey = num[pos];minkeypos = pos;}}return minkeypos;}void SelectSort(int *num, int n){int i, minkeypos = 0;for (i=0; i<n-1; i++) //选择第i+1小的记录，并交换到位{minkeypos = SelectMinKey(num, i, n);printf("i====%d minkeypos====%d/n",i, minkeypos);if (i != minkeypos){swap(&num[i], &num[minkeypos]);}}}//2-路归并排序void Merge(int *R,int low,int m,int high) {//将两个有序的子文件R[low..m)和R[m+1..high]归并成一个有序的子文件R[low..high] int i=low,j=m+1,p=0;int *R1;R1=(int *)malloc((high-low+1)*sizeof(int)); if(!R1)return; while(i<=m&&j<=high) //两子文件非空时取其小者输出到R1[p]上 R1[p++]=(R[i]<=R[j])?R[i++]:R[j++]; while(i<=m) //若第1个子文件非空，则复制剩余记录到R1中 R1[p++]=R[i++]; while(j<=high) //若第2个子文件非空，则复制剩余记录到R1中 R1[p++]=R[j++]; for(p=0,i=low;i<=high;p++,i++) R[i]=R1[p]; //归并完成后将结果复制回R[low..high] } void MergeSort(int R[],int low,int high) {//用分治法对R[low..high]进行二路归并排序 int mid; if(low<high){ //区间长度大于1 mid=(low+high)/2;//分解 MergeSort(R,low,mid);//递归地对R[low..mid]排序 MergeSort(R,mid+1,high);//递归地对R[mid+1..high]排序 Merge(R,low,mid,high);//组合，将两个有序区归并为一个有序区 } }