STLalgorithm算法find(16)
原文地址:http://www.cplusplus.com/reference/algorithm/find/
function template
std::find
template <class InputIterator, class T>
InputIterator find (InputIterator first, InputIterator last, const T& val);
Find value in range
Returns an iterator to the first element in the range [first,last)
that compares equal to val. If no such element is found, the function returns last.
返回范围内与val相等的第一个元素的迭代器,如果没有这样的元素,那么将返回last.
例子:
#include
#include
#include
#include
using namespace std;
void find2(){
vector
cout<<”vi=”;
for(int &i:vi)
cout<<i<<” “;
cout<<endl;
auto it=find(vi.begin(),vi.end(),8);
cout<<"auto it=find(vi.begin(),vi.end(),8);"<<endl;
cout<<"(it-1)="<<\*(it-1)<<endl;
cout<<"it="<<\*it<<endl;
cout<<"(it+1)="<<\*(it+1)<<endl;
auto it2=find(vi.begin(),vi.end(),18);
cout<<"auto it2=find(vi.begin(),vi.end(),18);"<<endl;
cout<<"(it2-1)="<<\*(it2-1)<<endl;
cout<<"it2="<<\*it2<<endl;
cout<<"(it2+1)="<<\*(it2+1)<<endl;
if(it2==vi.end())
cout<<"it2==vi.end()"<<endl;
}
运行截图:
The function uses operator==
to compare the individual elements to val.
使用operator==来比较元素与val是否相等。
The behavior of this function template is equivalent to:
1 | 1 |
1 | template<class InputIterator, class T> |
Parameters
first, last
Input iterators to the initial and final positions in a sequence. The range searched is [first,last)
, which contains all the elements between first and last, including the element pointed by first but not the element pointed bylast.
比较的范围。
val
Value to search for in the range.
T shall be a type supporting comparisons with the elements pointed by InputIterator using operator==
(with the elements as left-hand side operands, and val as right-hand side).
比较的值。
Return value
An iterator to the first element in the range that compares equal to val.
If no elements match, the function returns last.
返回范围内与val相等的第一个元素的迭代器,如果没有这样的元素,那么将返回last.
Example
1 | 1 |
1 | // find example |
Output:
Element found in myints: 30
Element found in myvector: 30
Complexity
Up to linear in the distance between first and last: Compares elements until a match is found.
Data races
Some (or all) of the objects in the range [first,last)
are accessed (once at most).
Exceptions
Throws if either an element comparison or an operation on an iterator throws.
Note that invalid arguments cause undefined behavior.
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转载请注明出处:http://blog.csdn.net/qq844352155
author:天下无双
Email:coderguang@gmail.com
2014-9-11
于GDUT
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- 本文作者: royalchen
- 本文链接: http://www.royalchen.com/2016/02/24/stlalgorithm算法find(16)/
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