算法之分冶法合併算法

   //遞歸分成小部分
    public void merge_sort(int[] arrays,int start,int end){
        if(start<end){
            int m=(start+end)/2;
            merge_sort(arrays,start,m);
            merge_sort(arrays,m+1,end);
            combin_arrays(arrays,start,m,end);    
        }
    }
    //合併數組
    public void combin_arrays(int[] arrays,int start,int m,int end){
        int length=end-start+1;
        int temp[]=new int[length];//用來存放比較的數組，用完複製回到原來的數組
        int i=start;
        int j=m+1;
        int c=0;
        while(i<=m &&j<=end){
            if(arrays[i]<arrays[j]){
                temp[c]=arrays[i];
                i++;
                c++;
            }else{
                temp[c]=arrays[j];
                j++;
                c++;
            }
        }
        while(i<=m){
            temp[c]=arrays[i];
            i++;
        }
        while(j<=end){
        temp[c]=arrays[j];
        j++;
        }
        c=0;
        for(int t=start;t<=end;t++,c++){
            arrays[t]=temp[c];
        }
        snp(arrays);
    }