劍指offer 第4題擴展

 

 

//已知兩個排好序的數組A1和A2，內存在A1的末尾有足夠多的空間來容納
//A2，設計算法把A2插入到A1後面，使整體有序


// 歸併排序思想，從後往前處理

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <iterator>
using namespace std;

void MergeSort(int arr1[], int arr2[],int len1,int len2)
{
	if(arr1 == NULL || arr2 == NULL || len1 < 0 || len2 < 0)
		return ;
	int i,j,k;
	int len = len1 + len2;
	i = len1 - 1;
	j = len2 - 1;
	k = len - 1;
	while(i >= 0 && j >= 0)
	{
		if(arr1[i] > arr2[j])
			arr1[k] = arr1[i--];
		else
			arr1[k] = arr2[j--];
		--k;
	}
	while(i >= 0)
	{
		arr1[k] = arr1[i];
		--k;
		--i;
	}
	while(j >= 0)
	{
		arr1[k] = arr2[j];
		--j;
		--k;
	}

}

int main()
{
	int a1[20] = { 1,3,5,8,10};
	int a2[5] = {2,4,6,9,12};
	MergeSort(a1,a2,5,5);
	copy(a1,a1 + 10,ostream_iterator<int>(cout," "));

	return 0;
	
}