vector<int> a(10,0);
for(vector<int>::iterator itor=a.begin();itor!=a.end();itor++)
*itor=1; /* *itor can't changed */
for(vector<int>::const_iterator itor=a.begin();itor!=a.end();itor++)
cout<<*itor;
/* itor itself can't changed,but *itor is changeable */
const vector<int>::iterator itor; bool singal;
cin>>singal;
计算数组长度
unsigned a[]={1,2,3,4,5,6,7,8,9,0};
cout<<sizeof(a)/sizeof(unsigned);