归并排序

#include<stdio.h>

void MergeArray(int first,int mid,int last,int a[])
{
    int k=0;
    int i=first,j=mid+1;
    int n=mid,m=last;
    int c[100];
    while(i<=n && j<=m)
    {
        if(a[i]<a[j]) c[k++]=a[i++];
        else c[k++]=a[j++];
    }
    while(i<=n) c[k++]=a[i++];
    while(j<=m) c[k++]=a[j++];
    for(i=0;i<k;i++) a[i+first]=c[i];
}

void MergeSort(int first,int last,int a[])
{
    if(first==last) return ;
    int mid=(first+last)/2;
    MergeSort(first,mid,a);
    MergeSort(mid+1,last,a);
    MergeArray(first,mid,last,a);
}

int main()
{
    int a[100],c[100],n;
    while(scanf("%d",&n))
    {
        for(int i=0;i<n;i++) scanf("%d",&a[i]);
        MergeSort(0,n-1,a);
        for(int i=0;i<n;i++) printf("%d ",a[i]);
        printf("\n");
    }
}