C ++跳過列表實現-返回值已損壞，內存泄漏？

Question

我想實現跳過列表，我的代碼不完整，需要更多的函數和變量，但是我處於開發它的這個級別，並且已經遇到了問題。

第160和133行應該返回相同的值，在本示例中為5，但不知何故它已損壞，並且160返回了一些奇怪的整數（我猜它訪問了一些未分配的內存）

我運行valgrind並得到以下信息：

height insert 5
b.second 5
==9440== Conditional jump or move depends on uninitialised value(s)
==9440==    at 0x40C21BD: std::ostreambuf_iterator<char, std::char_traits<char> > std::num_put<char, std::ostreambuf_iterator<char, std::char_traits<char> > >::_M_insert_int<long>(std::ostreambuf_iterator<char, std::char_traits<char> >, std::ios_base&, char, long) const (in /usr/lib/i386-linux-gnu/libstdc++.so.6.0.16)
==9440==    by 0x40C2502: std::num_put<char, std::ostreambuf_iterator<char, std::char_traits<char> > >::do_put(std::ostreambuf_iterator<char, std::char_traits<char> >, std::ios_base&, char, long) const (in /usr/lib/i386-linux-gnu/libstdc++.so.6.0.16)
==9440==    by 0x40CDEBB: std::ostream& std::ostream::_M_insert<long>(long) (in /usr/lib/i386-linux-gnu/libstdc++.so.6.0.16)
==9440==    by 0x40CE042: std::ostream::operator<<(int) (in /usr/lib/i386-linux-gnu/libstdc++.so.6.0.16)
==9440==    by 0x41654D2: (below main) (libc-start.c:226)
==9440== 
==9440== Use of uninitialised value of size 4
==9440==    at 0x40C1C53: ??? (in /usr/lib/i386-linux-gnu/libstdc++.so.6.0.16)
==9440==    by 0x40C21F0: std::ostreambuf_iterator<char, std::char_traits<char> > std::num_put<char, std::ostreambuf_iterator<char, std::char_traits<char> > >::_M_insert_int<long>(std::ostreambuf_iterator<char, std::char_traits<char> >, std::ios_base&, char, long) const (in /usr/lib/i386-linux-gnu/libstdc++.so.6.0.16)
==9440==    by 0x40C2502: std::num_put<char, std::ostreambuf_iterator<char, std::char_traits<char> > >::do_put(std::ostreambuf_iterator<char, std::char_traits<char> >, std::ios_base&, char, long) const (in /usr/lib/i386-linux-gnu/libstdc++.so.6.0.16)
==9440==    by 0x40CDEBB: std::ostream& std::ostream::_M_insert<long>(long) (in /usr/lib/i386-linux-gnu/libstdc++.so.6.0.16)
==9440==    by 0x40CE042: std::ostream::operator<<(int) (in /usr/lib/i386-linux-gnu/libstdc++.so.6.0.16)
==9440==    by 0x41654D2: (below main) (libc-start.c:226)
==9440== 
==9440== Conditional jump or move depends on uninitialised value(s)
==9440==    at 0x40C1C5C: ??? (in /usr/lib/i386-linux-gnu/libstdc++.so.6.0.16)
==9440==    by 0x40C21F0: std::ostreambuf_iterator<char, std::char_traits<char> > std::num_put<char, std::ostreambuf_iterator<char, std::char_traits<char> > >::_M_insert_int<long>(std::ostreambuf_iterator<char, std::char_traits<char> >, std::ios_base&, char, long) const (in /usr/lib/i386-linux-gnu/libstdc++.so.6.0.16)
==9440==    by 0x40C2502: std::num_put<char, std::ostreambuf_iterator<char, std::char_traits<char> > >::do_put(std::ostreambuf_iterator<char, std::char_traits<char> >, std::ios_base&, char, long) const (in /usr/lib/i386-linux-gnu/libstdc++.so.6.0.16)
==9440==    by 0x40CDEBB: std::ostream& std::ostream::_M_insert<long>(long) (in /usr/lib/i386-linux-gnu/libstdc++.so.6.0.16)
==9440==    by 0x40CE042: std::ostream::operator<<(int) (in /usr/lib/i386-linux-gnu/libstdc++.so.6.0.16)
==9440==    by 0x41654D2: (below main) (libc-start.c:226)
==9440== 
==9440== Conditional jump or move depends on uninitialised value(s)
==9440==    at 0x40C221A: std::ostreambuf_iterator<char, std::char_traits<char> > std::num_put<char, std::ostreambuf_iterator<char, std::char_traits<char> > >::_M_insert_int<long>(std::ostreambuf_iterator<char, std::char_traits<char> >, std::ios_base&, char, long) const (in /usr/lib/i386-linux-gnu/libstdc++.so.6.0.16)
==9440==    by 0x40C2502: std::num_put<char, std::ostreambuf_iterator<char, std::char_traits<char> > >::do_put(std::ostreambuf_iterator<char, std::char_traits<char> >, std::ios_base&, char, long) const (in /usr/lib/i386-linux-gnu/libstdc++.so.6.0.16)
==9440==    by 0x40CDEBB: std::ostream& std::ostream::_M_insert<long>(long) (in /usr/lib/i386-linux-gnu/libstdc++.so.6.0.16)
==9440==    by 0x40CE042: std::ostream::operator<<(int) (in /usr/lib/i386-linux-gnu/libstdc++.so.6.0.16)
==9440==    by 0x41654D2: (below main) (libc-start.c:226)
==9440== 
find main 68678181

我知道我需要刪除Car-Objects，但是我會在程序結尾處的某個地方刪除它，並且我不認為這是問題的原因。

如果有人可以告訴我我的錯誤以及為什么我的變量損壞了，那就太好了。

謝謝

Answer 1

該返回值未初始化，因為您的find方法是遞歸的。 您沒有將最終調用的結果傳播回main方法。

實際上，您的編譯器應警告您，find方法的路徑不返回值。 例如，如果r == NULL且（* anf）.down！= NULL，那么您最終將陷入方法的末尾而不返回任何內容。