问题
So I am trying to modify this code of vectors into lists. I understand vectors but fairly new to lists. This is what I have tried so Far how can I fix this Please let me Know. Here is the original vector code:
void insertion_sort(std::vector <int> &num) {
int i, j, key;
bool insertionNeeded = false;
for (j = 1; j < num.size(); j++) {
key = num[j];
insertionNeeded = false;
for (i = j - 1; i >= 0; i--) { // larger values move right
if (key < num[i]) {
num[i + 1] = num[i];
insertionNeeded = true;
}
else
break;
}
if (insertionNeeded)
num[i + 1] = key; //Put key into its proper location
}
}
Here is the code I tried to convert to Lists: I am getting an error when I run it
void insertion_sort(list<int> &li) {
int i, j, key;
bool insertionNeeded = false;
list<int>::iterator itr = li.begin();
for (j = 1; j < li.size(); j++) {
advance(itr, j);
key = *itr;
insertionNeeded = false;
for (i = j - 1; i >= 0; i--) { // larger values move right
advance(itr, i);
if (key < i) {
advance(itr, i + 1);
int temp1 = *itr;
advance(itr, i);
int temp2 = *itr;
temp1 = temp2;
insertionNeeded = true;
}
else
break;
}
if (insertionNeeded)
advance(itr, i + 1);
*itr = key;
}
}
回答1:
This is my quick answer. The test code is here.
Note that std::advance
modifies its argument.
OTOH, std::next
leaves its argument unmodified.
void insertion_sort(std::list<int> &li)
{
for (auto j = 1U; j < li.size(); ++j)
{
auto itr = li.begin();
std::advance(itr, j);
const auto key = *itr;
for (auto i = j; i > 0U; --i) // i is just a counter.
{
std::advance(itr, -1);
if (key < *itr) // larger values move right
{
const int temp = *itr;
*itr = key;
*std::next(itr) = temp;
}
else{
break;
}
}
}
}
来源:https://stackoverflow.com/questions/52807426/insertion-sort-using-a-list-stl-recursively