归并排序

/*归并排序*/#include <iostream>#include <cstdio>using namespace std;void merg( int *a,int sta,int mid,int end ){    int i,j,k;    int *b=new int[end-sta+1];    k=0 , i=sta , j=mid ;    while( i<mid && j<=end )    {        if( a[i]<a[j] ) b[k++]=a[i++];        else b[k++]=a[j++];    }    while( i<mid ) b[k++]=a[i++];    while( j<=end ) b[k++]=a[j++];    for( i=0;i<end-sta+1;i++ )        a[sta+i]=b[i];    delete b;}void mergsort( int *a,int sta,int end ){    int i,mid;    if( sta==end ) return;    else    {        mid=( sta+end )/2;        mergsort( a,sta,mid );        mergsort( a,mid+1,end );        merg( a,sta,mid+1,end );    }}int main(){    int i;    int a[10]={73,56,71,2,4,34,47,46,25,12};    mergsort( a,0,9 );    for( i=0;i<10;i++ )        cout<<a[i]<<" ";    cout<<endl;    return 0;}