如何删除hash_map 中的KEY - C++ Builder / Windows SDK/API
小弟最近用到hash_map 要通过遍历hash_map元素进行逻辑判断。 但是当我删除hash_map中的某个KEY对应的值后，
该key依然存在，请问如何将KEY和它所对应的值一并删除 。谢谢
[解决办法]
erase
[解决办法]
// hash_map_erase.cpp
// compile with: /EHsc
#define _DEFINE_DEPRECATED_HASH_CLASSES 0
#include <hash_map>
#include <iostream>
int main()
{
using namespace std;
using namespace stdext;
hash_map <int, int> hm1, hm2, hm3;
hash_map <int, int> :: iterator pIter, Iter1, Iter2;
int i;
hash_map <int, int>::size_type n;
typedef pair <int, int> Int_Pair;
for (i = 1; i < 5; i++)
{
hm1.insert(Int_Pair (i, i));
hm2.insert(Int_Pair (i, i*i));
hm3.insert(Int_Pair (i, i-1));
}
// The 1st member function removes an element at a given position
Iter1 = ++hm1.begin();
hm1.erase(Iter1);
cout < < "After the 2nd element is deleted, the hash_map hm1 is:";
for (pIter = hm1.begin(); pIter != hm1.end(); pIter++)
cout < < " " < < pIter -> second;
cout < < "." < < endl;
// The 2nd member function removes elements
// in the range [_First, _Last)
Iter1 = ++hm2.begin();
Iter2 = --hm2.end();
hm2.erase(Iter1, Iter2);
cout < < "After the middle two elements are deleted, "
< < "the hash_map hm2 is:";
for (pIter = hm2.begin(); pIter != hm2.end(); pIter++)
cout < < " " < < pIter -> second;
cout < < "." < < endl;
// The 3rd member function removes elements with a given _Key
n = hm3.erase(2);
cout < < "After the element with a key of 2 is deleted,\n"
< < "the hash_map hm3 is:";
for (pIter = hm3.begin(); pIter != hm3.end(); pIter++)
cout < < " " < < pIter -> second;
cout < < "." < < endl;
// The 3rd member function returns the number of elements removed
cout < < "The number of elements removed from hm3 is: "
< < n < < "." < < endl;
// The dereferenced iterator can also be used to specify a key
Iter1 = ++hm3.begin();
hm3.erase(Iter1);
cout < < "After another element with a key equal to that"
< < endl;
cout < < "of the 2nd element is deleted, "
< < "the hash_map hm3 is:";
for (pIter = hm3.begin(); pIter != hm3.end(); pIter++)
cout < < " " < < pIter -> second;
cout < < "." < < endl;
}
