我一直在解决我的链表上的一些内存泄漏问题：（目前编辑了 3 次以上，靠近底部）
以下是错误：
==348== HEAP SUMMARY:
==348== in use at exit: 32 bytes in 2 blocks
==348== total heap usage: 17 allocs, 15 frees, 272 bytes allocated
==348==
==348== 16 bytes in 1 blocks are definitely lost in loss record 1 of 2
==348== at 0x4C2B1C7: operator new(unsigned long) (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==348== by 0x400A2A: RangeSet::RangeSet() (RangeSet.cpp:14)
==348== by 0x4013ED: main (TestRange.cpp:16)
==348==
==348== 16 bytes in 1 blocks are definitely lost in loss record 2 of 2
==348== at 0x4C2B1C7: operator new(unsigned long) (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==348== by 0x400F54: RangeSet::Union(RangeSet const&, RangeSet const&) (RangeSet.cpp:167)
==348== by 0x401400: main (TestRange.cpp:17)
我可以从发布的类似问题中看出，这很可能是我释放“下一个”指针的问题，但我经历并修复了这些错误（至少我尝试过），现在我只能从运行中得到这个（^） valgrind --tool=memcheck --leak-check=yes
相关代码：
RangeSet::RangeSet()
{
// make a dummy node?
RNode* newNode = new RNode();
head = newNode;
head->start = 0;
head->end = 0;
head->next = NULL; // newing this for memory leak??
len=0;
} // end of constructor
// copy constructor for Union
RangeSet::RangeSet(const RangeSet &in)
{
RNode* cur;
RNode* nex;
head = new RNode();
head->start = in.head->start;
head->end = in.head->end;
cur = head;
nex = in.head->next;
while (nex){
cur->next = new RNode();
cur = cur->next;
cur->start = nex->start;
cur->end = nex->end;
nex = nex->next;
}
len = in.len;
} // end of copy constructor
// creates a pointer to new RangeSet that is the union of the two supplied RangeSets
RangeSet* RangeSet::Union(const RangeSet &alpha, const RangeSet &beta)
{
// alpha and beta are const, so create copy
RangeSet* copAlpha = new RangeSet(alpha);
RNode *cursor = beta.head;
// addRange all of beta into alpha's copy
while (cursor != NULL){
copAlpha->addRange(cursor->start, cursor->end);
cursor=cursor->next;
}
return copAlpha;
} // end of Union
问题可能出在我的 RNode 的构造函数上吗？
struct RNode {
int start, end;
RNode* next;
// possibly a pointer back to make it doubly linked
RNode() {
next = NULL;
}
};
编辑 对不起！这是我的删除函数（我的析构函数只是调用它）：
// makes the set empty
void RangeSet::deleteAllElements()
{
// having memory leak problems stemming from this function
// trying to fix
RNode *nex = head->next;
for (RNode* cursor = head; cursor; cursor=nex){
nex = cursor->next;
RNode *cur = cursor;
delete(cur);
//delete(cursor->next); // Should I do this in a constructor for the RNode
len--;
}
} // end of deleteAllElements
编辑 2 使用 addRange 更新和排序（最后由 addRange 调用）。感谢大家一直以来的帮助！（抱歉 addRange 有点冗长，可能令人费解）
// addRange
void RangeSet::addRange(int rangeStart, int rangeEnd)
{
// debug
//cout << "Adding range: " << rangeStart << " to " << rangeEnd << endl;
// li'l bit of error checking
if (rangeStart > rangeEnd){
cerr << "Please enter range(s) in the correct order. Exiting." << endl;
exit(0);
}
// head case
if (len==0){
head->start = rangeStart;
head->end = rangeEnd;
len++;
// need to account for adding at beginning
} else if (rangeStart <= head->start){
//cout << "INSERTING AT BEGINNING" << endl;
RNode *newNode = new RNode();
newNode->start = head->start;
newNode->end = head->end;
newNode->next = head->next;
head->start = rangeStart;
head->end = rangeEnd;
head->next = newNode;
len++;
} else if (head->next == NULL){
RNode *newNode = new RNode();
newNode->start = rangeStart;
newNode->end = rangeEnd;
head->next = newNode;
len++;
} else {
// Moving past any nodes where the start is less than rangeStart
RNode *cursor = head;
RNode *past = cursor;
int count = 1;
while (cursor!=NULL && count<=len){
if (rangeStart > cursor->start){
//cout << rangeStart << " is > than " << cursor->start << endl;
//cout << "DEBUG1(cursor): " << cursor->start << endl;
//cout << "DEBUG2(past): " << past->start << endl;
past = cursor;
cursor = cursor->next;
}
count++;
}
//cout << "INSERTING POS: " << count << endl;
// creating a new node to insert in middle
RNode *newNode = new RNode();
newNode->start = rangeStart;
newNode->end = rangeEnd;
if (count == 1){
// add it after head (no other nodes)
head->next = newNode;
newNode->next = NULL;
} else {
if (cursor){
newNode->next = cursor;
}
past->next = newNode;
}
len++;
}
//dump();
sort();
} // end addRange
所以我要做的是创建新节点并根据其起始值将其添加到列表中，然后调用 sort()：
// sort function called by addRange
void RangeSet::sort()
{
//cout << "SORTING" << endl;
RNode *cursor = head;
while (cursor->next != NULL){
RNode *curPlusOne = cursor->next;
if (cursor->end >= (curPlusOne->start -1)){
if (cursor->end < curPlusOne->end){
cursor->end = curPlusOne->end;
}
cursor->next = curPlusOne->next;
//cout << "NODE BEING DELETED: " << curPlusOne->start << " to " << curPlusOne->end << endl;
delete(curPlusOne);
len--;
} else {
cursor=cursor->next;
}
} // end while
//dump();
} // end sort
编辑 3发布我的主要和删除范围。这次我也遇到了一组不同的错误，我将在底部发布。再次感谢！
// deletes all integers from RANGESTART to RANGEEND inclusive
void RangeSet::deleteRange(int rangeStart, int rangeEnd)
{
RNode *cursor = head;
RNode *past = cursor;
RNode *temp = cursor->next;
while (cursor){
temp = cursor->next;
if (rangeStart <= cursor->start && rangeEnd >= cursor->end){
// case 1: if the entire node is encompassed by what is being deleted
if (cursor==head) { // still at head
head = head->next;
past = cursor;
delete(cursor);
} else {
past->next = cursor->next;
delete(cursor);
}
len--;
} else if (rangeStart<=cursor->start && rangeEnd>=cursor->start && rangeEnd<=cursor->end) {
// case 2: the rangeStart is smaller than node's rangeStart
cursor->start = rangeEnd+1;
len--;
} else if (rangeEnd>=cursor->end && rangeStart>=cursor->start && rangeStart<=cursor->end) {
// case 3: the rangeEnd is larger than node's rangeEnd
cursor->end = rangeStart-1;
len--;
} else if (cursor->start < rangeStart && cursor->end > rangeEnd){
// case 4: the range is in the middle of a node (split)
RNode *newNode = new RNode();
newNode->start = rangeEnd+1;
newNode->end = cursor->end;
newNode->next = cursor->next;
cursor->end=rangeStart-1;
cursor->next = newNode;
len--;
}
past = cursor;
cursor=temp;
} // end while
} // end of deleteRange
int main(){
RangeSet S, T;
S.addRange(5,10);
S.addRange(22,33);
S.addRange(4,6);
T.addRange(30,35);
RangeSet U;
U = *RangeSet::Union(T,S);
U.addRange(1,1);
U.addRange(39,40);
U.addRange(40,150);
RangeSet B(U);
if (B==U)
cout << "COPY CONSTRUCTOR + OVERLOADED OPERATOR WORKED!" << endl;
U.dump();
cout << endl;
U.deleteRange(1,35);
U.deleteRange(75,100);
U.dump();
}
这是我在运行 valgrind 时收到的新错误（我之前收到过，但我以为我已经修复了它们）：
==22482== Invalid read of size 8
==22482== at 0x40122D: RangeSet::deleteAllElements() (RangeSet.cpp:237)
==22482== by 0x400B79: RangeSet::~RangeSet() (RangeSet.cpp:47)
==22482== by 0x401524: main (TestRange.cpp:30)
==22482== Address 0x5a03368 is 8 bytes inside a block of size 16 free'd
==22482== at 0x4C2A4BC: operator delete(void*) (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==22482== by 0x401261: RangeSet::deleteAllElements() (RangeSet.cpp:241)
==22482== by 0x400B79: RangeSet::~RangeSet() (RangeSet.cpp:47)
==22482== by 0x401500: main (TestRange.cpp:30)
这就是为什么我认为我的问题必须在 deleteAllElements 中，但我仍然很难过！
编辑 4请注意，主要功能是根据提供给我的骨架改编的，因此如果存在问题，我无法做太多更改。