#include "../inc/numeric_.h"
#include <algorithm>
#include <numeric>
#include <iostream>
#include <vector>
#include <list>
#include <string>
#include <functional>
using namespace std;
using namespace std::placeholders;
void use_numeric()
{
 vector<int> nvec = {1, 2, 3, 4, 5, 6, 7};
 //调用accumulate累加,sum的初始值为0,累加结果写入sum
 auto sum = accumulate(nvec.begin(), nvec.end(), 0);
 cout << "sum is " << sum << endl;
 list<string> strlist = {"hello", "zack", "good", "idea"};
 string stradd = accumulate(strlist.begin(), strlist.end(), string(""));
 cout << "str add result is " << stradd << endl;
 list<string> strlist2 = {"hello", "zack", "good", "idea"};
 bool bequa = equal(strlist.begin(), strlist.end(), strlist2.begin());
 if (bequa)
 {
 cout << "strlist is equal to strlist2" << endl;
 }
 else
 {
 cout << "strlist is not equal to strlist2" << endl;
 }

 vector<int> nvec2 = {1, 2, 3, 4};
 //将nvec2中所有元素设置为0
 fill(nvec2.begin(), nvec2.end(), 0);
 //将nvec2中前半部分设置为10
 fill(nvec2.begin(), nvec2.begin() + nvec2.size() / 2, 10);
 vector<int> vec;
 fill_n(vec.begin(), vec.size(), 0);

 //空vector
 vector<int> nvec4;
 // back_inserter绑定nvec4并返回迭代器
 auto iter = back_inserter(nvec4);
 //对迭代器的赋值就是对nvec插入元素
 *iter = 2;
 *iter = 4;
 for (auto it = nvec4.begin(); it != nvec4.end(); it++)
 {
 cout << *it << " ";
 }
 cout << endl;

 //空vector
 vector<int> nvec5;
 // back_inserter绑定nvec5并返回迭代器
 auto iter5 = back_inserter(nvec5);
 fill_n(iter5, 10, 0);

 int a1[] = {0, 1, 2, 3, 4, 5, 6};
 constexpr int nszie = sizeof(a1) / sizeof(int);
 int a2[nszie];
 //将a1内容copy到a2中
 copy(begin(a1), end(a1), a2);

 vector<int> nvec6 = {1, 2, 3, 4};
 //将nvec6中所有元素为3的设置为32
 replace(nvec6.begin(), nvec6.end(), 3, 32);

 //原始数据列表
 list<int> ilist = {0, 1, 2, 3, 4, 5};
 //空向量
 vector<int> rcpvec;
 //将ilist中的数据copy到rcpvec里,但是将其中的0替换为42
 replace_copy(ilist.begin(), ilist.end(), back_inserter(rcpvec), 0, 42);
}

void erase_dup(vector<string> &words)
{
 //先将words中的词语排序
 sort(words.begin(), words.end());
 // unique会移动元素,将不重复的元素放在前边,重复的放在后边
 // unique返回不重复的最后一个元素的位置
 const auto uniqueiter = unique(words.begin(), words.end());
 //调用erase将重复的元素删除
 words.erase(uniqueiter, words.end());

 // for (auto it = words.begin(); it != words.end(); it++)
 // {
 // cout << *it << " ";
 // }
 // cout << endl;
}

bool isShort(const string &s1, const string &s2)
{
 return s1.size() < s2.size();
}

void use_predicate()
{
 vector<string> words = {"hello", "za", "zack", "no matter", "what"};
 sort(words.begin(), words.end(), isShort);
 for (auto it = words.begin(); it != words.end(); it++)
 {
 cout << *it << endl;
 }
}

void use_lambda()
{
 auto f = []()
 { return 42; };
 cout << " f is " << f() << endl;

 [](const string &s1, const string &s2) -> bool
 { return s1.size() < s2.size(); };
 vector<string> words = {"hello", "za", "zack", "no matter", "what"};
 stable_sort(words.begin(), words.end(), [](const string &s1, const string &s2) -> bool
 { return s1.size() < s2.size(); });
 for (auto it = words.begin(); it != words.end(); it++)
 {
 cout << *it << endl;
 }
}

int use_bigger(int sz)
{
 vector<string> words = {"hello", "za", "zack", "no matter", "what"};
 //先排序去除重复单词
 erase_dup(words);
 //再稳定排序,按照长度有小到大
 stable_sort(words.begin(), words.end(), [](const string &s1, const string &s2) -> bool
 { return s1.size() < s2.size(); });
 auto findit = find_if(words.begin(), words.end(), [sz](const string &s)
 { return s.size() > sz; });
 for_each(findit, words.end(), [](const string &s)
 { cout << s << " "; });
 cout << endl;
 return words.end() - findit;
}

void lambda_catch()
{
 int val = 10;
 auto fn = [val]
 { return val; };
 val = 200;
 auto fv = fn();
 cout << "fv is " << fv << endl;
}

void lambda_catch_r()
{
 int val = 10;
 auto fn = [&val]
 { return val; };
 val = 200;
 auto fv = fn();
 cout << "fv is " << fv << endl;
}

int use_bigger2(ostream &os, char c, int sz)
{
 vector<string> words = {"hello", "za", "zack", "no matter", "what"};
 //先排序去除重复单词
 erase_dup(words);
 //再稳定排序,按照长度有小到大
 stable_sort(words.begin(), words.end(), [](const string &s1, const string &s2) -> bool
 { return s1.size() < s2.size(); });
 auto findit = find_if(words.begin(), words.end(), [sz](const string &s)
 { return s.size() > sz; });
 // os 按照引用方式捕获,其余变量c 通过= 值方式隐士捕获。
 for_each(findit, words.end(), [=, &os](const string &s)
 { os << s << c; });

 // c 按照值的方式捕获,其余按照引用方式捕获。
 for_each(findit, words.end(), [&, c](const string &s)
 { os << s << c; });
 cout << endl;
 return words.end() - findit;
}

void mutalble_lam()
{
 int val = 100;
 auto fn = [val]() mutable
 {
 return ++val;
 };

 cout << "val is " << val << endl;

 cout << "fn val is " << fn() << endl;

 val = 200;
 cout << "val is " << val << endl;

 cout << "fn val is " << fn() << endl;
}

void rt_lambda()
{
 vector<int> nums = {-1, 2, 3, -5, 6, 7, -9};
 transform(nums.begin(), nums.end(), nums.begin(), [](int a)
 { return a < 0 ? -a : a; });
 for_each(nums.begin(), nums.end(), [](int a)
 { cout << a << endl; });

 transform(nums.begin(), nums.end(), nums.begin(), [](int a) -> int
 { if (a < 0) return -a; else return a; });
}

bool check_size(const string &str, int sz)
{
 if (str.size() > sz)
 {
 return true;
 }

 return false;
}

void calsize_count()
{
 string str = "hello";
 //将check_size第一个参数绑定给bind_check
 auto bind_check = bind(check_size, _1, 6);
 //相当于调用check_size(str,6)
 bool bck = bind_check(str);
 if (bck)
 {
 cout << "check res is true" << endl;
 }
 else
 {
 cout << "check res is false" << endl;
 }
}

int use_bigger3(ostream &os, char c, int sz)
{
 vector<string> words = {"hello", "za", "zack", "no matter", "what"};
 //先排序去除重复单词
 erase_dup(words);
 //再稳定排序,按照长度有小到大
 stable_sort(words.begin(), words.end(), [](const string &s1, const string &s2) -> bool
 { return s1.size() < s2.size(); });
 auto findit = find_if(words.begin(), words.end(), bind(check_size, _1, sz));

 // c 按照值的方式捕获,其余按照引用方式捕获。
 for_each(findit, words.end(), [&, c](const string &s)
 { os << s << c; });
 cout << endl;
 return words.end() - findit;
}