Arkadiy 的想法是正确的。如果你创建一个指针数组并对其进行排序,就可以原地排序:
#define NN 7
#define LL 4
int array[NN*LL] = {
3, 5, 5, 5,
3, 6, 6, 6,
4, 4, 4, 4,
4, 3, 3, 3,
2, 2, 2, 2,
2, 0, 0, 0,
1, 1, 1, 1
};
struct IntPtrArrayComp {
int length;
IntPtrArrayComp(int len) : length(len) {}
bool operator()(int* const & a, int* const & b) {
for (int i = 0; i < length; ++i) {
if (a[i] < b[i]) return true;
else if (a[i] > b[i]) return false;
}
return false;
}
};
void sortArrayInPlace(int* array, int number, int length)
{
int** ptrs = new int*[number];
int** span = ptrs;
for (int* a = array; a < array+number*length; a+=length) {
*span++ = a;
}
std::sort(ptrs, ptrs+number, IntPtrArrayComp(length));
int* buf = new int[number];
for (int n = 0; n < number; ++n) {
int offset = (ptrs[n] - array)/length;
if (offset == n) continue;
int* a_n = array+n*length;
std::move(a_n, a_n+length, buf);
std::move(ptrs[n], ptrs[n]+length, a_n);
std::move(buf, buf+length, ptrs[n]);
int find = 0;
for (int i = n+1; i < number; ++i) {
if (ptrs[i] == a_n) {
find = i;
break;
}
}
ptrs[find] = ptrs[n];
}
delete[] buf;
delete[] ptrs;
}
int main()
{
for (int n = 0; n< NN; ++n) {
for (int l = 0; l < LL; ++l) {
std::cout << array[n*LL+l];
}
std::cout << std::endl;
}
std::cout << "----" << std::endl;
sortArrayInPlace(array, NN, LL);
for (int n = 0; n< NN; ++n) {
for (int l = 0; l < LL; ++l) {
std::cout << array[n*LL+l];
}
std::cout << std::endl;
}
return 0;
}
输出:
3555
3666
4444
4333
2222
2000
1111
----
1111
2000
2222
3555
3666
4333
4444