《劍指offer》面試題4（合併數組）

#include <iostream>

using namespace std;
void mergeArray(int *A1,int& length1, int*A2, int length2)//把A2合併到A1中,假設A1，A2中的元素是從小到大
{
    if(A1==NULL || A2==NULL || length1<0 || length2<0) return;
    int p1 = length1-1, p2 = length2-1;
    length1 += length2;
    int p = length1-1;
    while(p2>=0 && p1>=0)
    {
        A1[p--] = A1[p1]>A2[p2]?A1[p1--]:A2[p2--];
    }
    while(p2>=0)
    {
        A1[p--] = A2[p2--];
    }
    /*while(p1>=0)            //可不寫
    {
        A1[p--] = A2[p1--];
    }*/
}
int main()
{
    int* a = new int[5];
    int lena = 2;
    a[0] = 2;a[1] = 7;
    int b[] = {3,8};
    mergeArray(a,lena,b,2);
    for(int i=0;i<lena;i++)
        cout<<a[i]<<" ";
    cout<<endl;
    return 0;
}