我正在尝试为字符串的数组列表实现合并排序算法,但我似乎找不到破坏数组列表排序的错误。
private static void sort(java.util.ArrayList<String> a)
{
// End recursion
if (a.size() < 2)
{
return;
}
int mid = a.size() / 2;
java.util.ArrayList<String> left = new java.util.ArrayList<String>();
int i;
for (i = 0; i < mid; i++)
{
left.add(a.remove(i));
}
java.util.ArrayList<String> right = new java.util.ArrayList<String>();
// Copy the second half to the "right"
for ( ; i < a.size(); i++)
{
right.add(a.remove(i));
}
sort(left);
sort(right);
merge(a, left, right);
}
private static void merge(java.util.ArrayList<String> result, java.util.ArrayList<String> left,java.util.ArrayList<String> right)
{
int i, l, r;
i = l = r = 0;
while (l < left.size() && r < right.size())
{
if ((left.get(l)).compareTo(right.get(r)) < 0)
{
result.add(left.get(l));
l++;
}
else
{
result.add(right.get(r));
r++;
}
i++;
}
while (l < left.size())
{
result.add(left.get(l));
l++;
i++;
}
// Append rest of the values in the right half, if any...
while (r < right.size())
{
result.add(right.get(r));
r++;
i++;
}
}