轉載地址: http://www.cppblog.com/zgysx/archive/2006/12/28/16944.html
刪除所有偶數項,並打印出刪除的項
1. vector/queue
正確方法1:
void erase(vector<int> &v)
{
for(vector<int>::iterator vi=v.begin();vi!=v.end();)
{
if(*vi % 2 == 0)
{
cout << "Erasing " << *vi << endl;
vi = v.erase(vi);
}
else ++vi;
}
}
正確方法2:
void erase2(vector<int> &v)
{
for(vector<int>::reverse_iterator ri=v.rbegin();ri!=v.rend();)
{
if(*ri % 2 == 0)
{
cout << "Erasing " << *ri << endl;
v.erase((++ri).base()); //erase()函數期待的是正向iterator,故而這裏要調
//用base()函數將逆向iterator轉換爲正向的
}
else ++ri;
}
}
2.map/list
正確方法
void erase(map<int,int> &m)
{
for(map<int,int>::iterator mi=m.begin();mi!=m.end();)
{
if(mi->second % 2 == 0)
{
cout << "Erasing " << mi->second << endl;
m.erase(mi++);
}
else ++mi;
}
}