这是我在钱能的书上照抄下来的，为什么不对？
而且它自己提供的源代码运行也出错，请各位大哥帮忙解决一下。
另外谁能给我讲讲里面那个replace()的用法及含义啊？
自己刚刚自学，请各位前辈指教啊！
#include <iostream>
#include <algorithm>
using namespace std;
void main()
{
string a,s1= "hello ";
string s2= "123 ";
cout < <(a==s1 ? " " : "not ") < < "equal\n ";
cout < <a+s2 < <endl;
reverse(a.begin(),a.end());
cout < <a < <endl;
cout < <a.replace(0,9,9, 'c ');
cout < <(s1.find( "ell ")!=-1? " ": "not ") < < "found\n ";
cout < <(s1.find( 'c ')!=-1 ? " " : "not ") < < "found\n ";
}
[解决办法]
#include <iostream>
#inlcude <string> -----------------------add this.
#include <algorithm>
using namespace std;
void main()
{
string a,s1= "hello ";
string s2= "123 ";
cout < <(a==s1 ? " " : "not ") < < "equal\n ";
cout < <a+s2 < <endl;
reverse(a.begin(),a.end());
cout < <a < <endl;
cout < <a.replace(0,9,9, 'c ');
cout < <(s1.find( "ell ")!=-1? " ": "not ") < < "found\n ";
cout < <(s1.find( 'c ')!=-1 ? " " : "not ") < < "found\n ";
}
[解决办法]
#include <iostream>
#include <string>
#include <algorithm>
using namespace std;
void main()
{
string a,s1= "hello ";
string s2= "123 ";
cout < <(a==s1 ? " " : "not ") < < "equal\n ";
cout < <a+s2 < <endl;
reverse(a.begin(),a.end());
cout < <a < <endl;
cout < <a.replace(0,9,9, 'c ');
cout < <(s1.find( "ell ")!=-1? " ": "not ") < < "found\n ";
cout < <(s1.find( 'c ')!=-1 ? " " : "not ") < < "found\n ";
}
[解决办法]
Examines each element in a range and replaces it if it matches a specified value.
template <class ForwardIterator, class Type>
void replace(
ForwardIterator _First,
ForwardIterator _Last,
const Type& _OldVal,
const Type& _NewVal
);
Parameters
_First
A forward iterator pointing to the position of the first element in the range from which elements are being replaced.
_Last
A forward iterator pointing to the position one past the final element in the range from which elements are being replaced.
_OldVal
The old value of the elements being replaced.
_NewVal
The new value being assigned to the elements with the old value.
Remarks
The range referenced must be valid; all pointers must be dereferenceable and within the sequence the last position is reachable from the first by incrementation.
The order of the elements not replaced remains stable.
The operator== used to determine the equality between elements must impose an equivalence relation between its operands.
The complexity is linear; there are (_Last – _First) comparisons for equality and at most (_Last – _First) assignments of new values.
Example
// alg_replace.cpp
// compile with: /EHsc
#include <vector>
#include <algorithm>
#include <iostream>
int main( ) {
using namespace std;
vector <int> v1;
vector <int> ::iterator Iter1;
int i;
for ( i = 0 ; i <= 9 ; i++ )
{
v1.push_back( i );
}
int ii;
for ( ii = 0 ; ii <= 3 ; ii++ )
{
v1.push_back( 7 );
}
random_shuffle (v1.begin( ), v1.end( ) );
cout < < "The original vector v1 is:\n ( " ;
for ( Iter1 = v1.begin( ) ; Iter1 != v1.end( ) ; Iter1++ )
cout < < *Iter1 < < " ";
cout < < "). " < < endl;
// Replace elements with a value of 7 with a value of 700
replace (v1.begin( ), v1.end( ), 7 , 700);
cout < < "The vector v1 with a value 700 replacing that of 7 is:\n ( " ;
for ( Iter1 = v1.begin( ) ; Iter1 != v1.end( ) ; Iter1++ )
cout < < *Iter1 < < " ";
cout < < "). " < < endl;
}
Output
The original vector v1 is:
( 7 1 9 2 0 7 7 3 4 6 8 5 7 7 ).
The vector v1 with a value 700 replacing that of 7 is:
( 700 1 9 2 0 700 700 3 4 6 8 5 700 700 ).
