数据结构之归并排序

  1 #include <stdio.h>
  2 #include <stdlib.h>
  3 #include <time.h>
  4 #define MAXSIZE 100000000
  5 #define INCREMENTNUM 200000
  6 #define EQ(a,b) ((a)==(b))
  7 typedef struct List{
  8     int*elem;
  9     int length;
 10     int size;
 11 }List;
 12 
 13 void initList(List &list)
 14 {
 15     list.elem=(int*)malloc(sizeof(int)*(MAXSIZE+1));
 16     if(!list.elem){
 17          printf("%s\n","初始化失败");
 18         exit(0);
 19     }
 20     list.length=0;
 21     list.size=MAXSIZE;
 22     printf("%s\n","初始化成功");
 23 }
 24 
 25 void insert(List &list ,int value)
 26 {
 27     if(list.length>=list.size){
 28         list.elem=(int*)realloc(list.elem,sizeof(int)*(list.length+INCREMENTNUM));
 29         if(!list.elem){
 30          printf("%s\n","内存重新分配失败");
 31         exit(0);
 32         }
 33         printf("%s\n","内存重新分配成功");
 34     list.size+=INCREMENTNUM;
 35     }
 36     list.elem[++list.length]=value; //第一从1开始
 37     //printf("%d%s  位置：%d\n",value,"\t插入成功",list.length);
 38 }
 39 
 40 
 41 void printList(List list)
 42 {
 43     //printf("共%d数据\n",list.length);
 44     int i;
 45     for(i=1;i<=list.length;i++){
 46         printf("%d\t",list.elem[i]);
 47     }
 48     printf("\n");
 49 
 50 }
 51 //归并
 52 void Merge(List L1,List &L2,int i,int m,int n)
 53 {
 54     int j;
 55     int k;
 56     for(j=m+1,k=i;j<=n&&i<=m;++k)
 57     {
 58         if(L1.elem[i]<L1.elem[j]) L2.elem[k]=L1.elem[i++];
 59         else  L2.elem[k]=L1.elem[j++];
 60     }
 61     if(i<=m)
 62     {
 63         while(i<=m){
 64             L2.elem[k++]=L1.elem[i++];
 65         }
 66     }
 67     if(j<=n)
 68     {
 69         while(j<=n){
 70             L2.elem[k++]=L1.elem[j++];
 71         }
 72     }
 73 }
 74 void MSort(List L1,List &L2,int s,int t)
 75 {
 76     if(s==t) L2.elem=L1.elem;
 77     else
 78     {
 79         List L3;
 80         L3.elem=(int*)malloc(sizeof(int)*(t-s+1));
 81         int m=(s+t)/2;
 82         MSort(L1,L3,s,m);
 83         MSort(L1,L3,m+1,t);
 84         Merge(L3,L2,s,m,t);
 85     }
 86 
 87 }
 88 void MergeSort(List &L)
 89 {
 90     MSort(L,L,1,L.length);
 91 }
 92 
 93 
 94 int main()
 95 {
 96 
 97     List list;
 98     initList(list);
 99     insert(list,49);insert(list,38);insert(list,65);insert(list,97);insert(list,76);
100     insert(list,13);insert(list,27);insert(list,49);
101     printList(list);
102     MergeSort(list);
103     printf("排序后\n");
104     printList(list);
105     return 0;
106 }