1. 简介
| 函数 |
作用 |
文档 |
find(beg,end,val) |
利用==操作符，对[beg,end)的元素与val进行比较。当匹配时结束搜索，返回该元素的InputIterator。 |
find() |
find_if(beg,end,pred) |
使用函数pred代替==操作符执行find()。 |
find_if() |
find_first_of(beg1,end1,beg2,end2) |
在[beg1,end1)范围内查找[beg2,end2)中任意一个元素的第一次出现。返回该元素的Iterator。 |
find_first_of() |
find_first_of(beg1,end1,beg2,end2,pred) |
使用函数pred代替==操作符执行find_first_of()。返回该元素的Iterator。 |
find_first_of() |
find_end(beg1,end1,beg2,end2) |
在[beg1,end1)范围内查找[beg2,end2)最后一次出现。找到则返回最后一对的第一个ForwardIterator，否则返回end1。 |
find_end() |
find_end(beg1,end1,beg2,end2,pred) |
使用函数pred代替==操作符执行find_end()。返回该元素的Iterator。 |
find_end() |
adjacent_find(beg,end) |
对[beg,end)的元素，查找一对相邻重复元素，找到则返回指向这对元素的第一个元素的ForwardIterator。否则返回end。 |
adjacent_find() |
adjacent_find(beg,end,pred) |
使用函数pred代替==操作符执行adjacent_find()。 |
adjacent_find() |
2. 示例代码
// find example
#include <iostream> // std::cout
#include <algorithm> // std::find
#include <vector> // std::vector
int main () {
// using std::find with array and pointer:
int myints[] = { 10, 20, 30, 40 };
int * p;
p = std::find (myints, myints+4, 30);
if (p != myints+4)
std::cout << "Element found in myints: " << *p << '\n';
else
std::cout << "Element not found in myints\n";
// using std::find with vector and iterator:
std::vector<int> myvector (myints,myints+4);
std::vector<int>::iterator it;
it = find (myvector.begin(), myvector.end(), 30);
if (it != myvector.end())
std::cout << "Element found in myvector: " << *it << '\n';
else
std::cout << "Element not found in myvector\n";
return 0;
}
// find_if example
#include <iostream> // std::cout
#include <algorithm> // std::find_if
#include <vector> // std::vector
bool IsOdd (int i) {
return ((i%2)==1);
}
int main () {
std::vector<int> myvector;
myvector.push_back(10);
myvector.push_back(25);
myvector.push_back(40);
myvector.push_back(55);
std::vector<int>::iterator it = std::find_if (myvector.begin(), myvector.end(), IsOdd);
std::cout << "The first odd value is " << *it << '\n';
return 0;
}
// find_first_of example
#include <iostream> // std::cout
#include <algorithm> // std::find_first_of
#include <vector> // std::vector
#include <cctype> // std::tolower
bool comp_case_insensitive (char c1, char c2) {
return (std::tolower(c1)==std::tolower(c2));
}
int main () {
int mychars[] = {'a','b','c','A','B','C'};
std::vector<char> haystack (mychars,mychars+6);
std::vector<char>::iterator it;
int needle[] = {'A','B','C'};
// using default comparison:
it = find_first_of (haystack.begin(), haystack.end(), needle, needle+3);
if (it!=haystack.end())
std::cout << "The first match is: " << *it << '\n';
// using predicate comparison:
it = find_first_of (haystack.begin(), haystack.end(),
needle, needle+3, comp_case_insensitive);
if (it!=haystack.end())
std::cout << "The first match is: " << *it << '\n';
return 0;
}
// find_end example
#include <iostream> // std::cout
#include <algorithm> // std::find_end
#include <vector> // std::vector
bool myfunction (int i, int j) {
return (i==j);
}
int main () {
int myints[] = {1,2,3,4,5,1,2,3,4,5};
std::vector<int> haystack (myints,myints+10);
int needle1[] = {1,2,3};
// using default comparison:
std::vector<int>::iterator it;
it = std::find_end (haystack.begin(), haystack.end(), needle1, needle1+3);
if (it!=haystack.end())
std::cout << "needle1 last found at position " << (it-haystack.begin()) << '\n';
int needle2[] = {4,5,1};
// using predicate comparison:
it = std::find_end (haystack.begin(), haystack.end(), needle2, needle2+3, myfunction);
if (it!=haystack.end())
std::cout << "needle2 last found at position " << (it-haystack.begin()) << '\n';
return 0;
}
// adjacent_find example
#include <iostream> // std::cout
#include <algorithm> // std::adjacent_find
#include <vector> // std::vector
bool myfunction (int i, int j) {
return (i==j);
}
int main () {
int myints[] = {5,20,5,30,30,20,10,10,20};
std::vector<int> myvector (myints,myints+8);
std::vector<int>::iterator it;
// using default comparison:
it = std::adjacent_find (myvector.begin(), myvector.end());
if (it!=myvector.end())
std::cout << "the first pair of repeated elements are: " << *it << '\n';
//using predicate comparison:
it = std::adjacent_find (++it, myvector.end(), myfunction);
if (it!=myvector.end())
std::cout << "the second pair of repeated elements are: " << *it << '\n';
return 0;
}
3. 练习
