数据结构 排序 归并排序

头文件：

#define MAXSIZE20

#define EQ(a,b)((a)==(b))
#define LT(a,b)((a)<(b))
#define LQ(a,b)((a)<=(b))

typedef int KeyType;

typedef int InfoType;

typedef struct ... {
KeyTypekey;
InfoTypeotherinfo;
} RedType;

typedef struct ... {
RedTyper[MAXSIZE+1];
intlength;
} SqList;

源文件：

#include " sort.h "

#include " stdio.h "

void init(SqList & s, int w[], int n) ... {
s.length=n;
for(inti=1;i<=n;i++)...{
s.r[i].key=w[i-1];
}
}

void show(SqLists) ... {
for(inti=1;i<=s.length;i++)...{
printf("%d ",s.r[i]);
}
printf(" ");
}

// mergethesr[i...m]andsr[m+1...n]totr[i...n].
void merge(RedTypesr[],RedTypetr[], int i, int m, int n) ... {
intj,k;

for(j=m+1,k=i;i<=m&&j<=n;k++)...{
if(LQ(sr[i].key,sr[j].key))...{
tr[k]=sr[i++];
}else...{
tr[k]=sr[j++];
}
}

//copytheleftofsr[i...m]
if(i<=m)...{
for(intt=0;t<=m-i;t++)...{
tr[k+t]=sr[i+t];
}
}

//copytheleftofsr[m+1...n]
if(j<=n)...{
for(intt=0;t<=n-j;t++)...{
tr[k+t]=sr[j+t];
}
}
}

// mergesortsrandstoreintr.
void mSort(RedTypesr[],RedTypetr[], int s, int t) ... {
if(s==t)...{
tr[s]=sr[s];
}else...{
intm=(s+t)/2;
RedTypetr2[MAXSIZE+1];

mSort(sr,tr2,s,m);
mSort(sr,tr2,m+1,t);
merge(tr2,tr,s,m,t);
}
}

void mergeSort(SqList & s) ... {
mSort(s.r,s.r,1,s.length);
}

void main() ... {
intw[]=...{49,38,65,97,76,13,27,49};
intn=8;

SqLists;
init(s,w,n);

mergeSort(s);
printf("aftermergesort: ");
show(s);
}

程序运行结果：

aftermergesort:
13 27 38 49 49 65 76 97
Pressanykeyto continue

说明：

算法的复杂度为O（n * log(n)），是一种稳定的排序方法。