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谁能不能帮我看看这个归并排序该怎么改正确啊?

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悬赏园豆:10 [已关闭问题] 关闭于 2015-06-13 14:23
 1 #include <iostream>
 2 using namespace std;
 3 
 4 void Merge(int a[], int p, int q, int r)
 5 {
 6     int n1 = q - p + 1;
 7     int n2 = r - q + 1;
 8     int *L = new int [n1+1];
 9     int *R = new int [n2+1];
10     int i, j, k;
11     for (i = 0; i < n1; i ++)
12         L[i] = a[p+i];
13     for (j = 0; j < n2; j ++)
14         R[j] = a[q+j];
15     
16     L[n1] = 0xFFFF, R[n2] = 0xFFFF; 
17     
18     i = 0; j = 0;
19     for (k = p; k <= r; k ++){
20         if (L[i] <= R[j])
21             a[k] = L[i++];
22         else 
23             a[k] = R[j++];
24     }
25 }
26 
27 void Merge_sort(int a[], int p, int r)
28 {
29     if (p < r){
30         int q = (p + r)/2;
31         Merge_sort(a, p, q);
32         Merge_sort(a, q+1, r);
33         Merge(a, p, q, r);
34     }
35 }
36 
37 int main()
38 {
39     int a[] = {4, 2, 1, 8, 5, 3, 9, 2, 0};
40     int n = sizeof(a)/ sizeof(a[0]);
41     Merge_sort(a, 0, n-1);
42     for (int i = 0; i < n; i++)
43         cout << a[i] << " ";
44     cout << endl;
45     return 0;
46 }

我能看出来有些地方有错误,但是不知道怎么改啊?有没有哪位大哥能教教我怎么改正确啊?

ii沙漠的主页 ii沙漠 | 初学一级 | 园豆:114
提问于:2015-06-13 14:07
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#include <iostream>
using namespace std;

void Merge(int a[], int p, int q, int r)
{
int n1 = q - p + 1;
int n2 = r - q;
int *L = new int[n1 + 1];
int *R = new int[n2 + 1];
int i, j, k;
for (i = 0; i < n1; i++)
L[i] = a[p + i];
for (j = 0; j < n2; j++)
R[j] = a[q + j + 1];

L[n1] = 0xFFFF, R[n2] = 0xFFFF;

i = 0; j = 0;
for (k = p; k <= r; k++){
if (L[i] <= R[j])
a[k] = L[i++];
else
a[k] = R[j++];
}
}

void Merge_sort(int a[], int p, int r)
{
if (p < r){
int q = (p + r) / 2;
Merge_sort(a, p, q);
Merge_sort(a, q + 1, r);
Merge(a, p, q, r);
}
}

int main()
{
int a[] = { 4, 2, 1, 8, 5, 3, 9, 2, 0 };
int n = sizeof(a) / sizeof(a[0]);
Merge_sort(a, 0, n - 1);
for (int i = 0; i < n; i++)
cout << a[i] << " ";
cout << endl;
return 0;
}

ii沙漠 | 园豆:114 (初学一级) | 2015-06-13 14:23
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