合并排序

合并排序

# include<iostream>
# include<cstdio>
using namespace std;
void MergeArray(int a[],int alen,int b[],int blen)
{
    int len = alen + blen -1;
    alen--;
    blen--;
    while(alen >= 0 && blen >= 0)
    {
        if(a[alen] > b[blen])
        {
            a[len--] = a[alen--];
        }
        else
        {
            a[len--] = b[blen--];
        }
    }
    while (alen>=0)
    {
        a[len--]=a[alen--];
    }
    while (blen>=0)
    {
        a[len--]=b[blen--];
    }
}
int main()
{
    int a[]= {2,4,6,8,10,0,0,0,0,0};//必须这样，留够空间
    int b[]= {1,3,5,7,9};
    MergeArray(a,5,b,5);
    for (int i=0; i<sizeof(a)/sizeof(a[0]); i++)
    {
        cout<<a[i]<<" ";
    }
}