习题答案目录：https://www.cnblogs.com/Mered1th/p/10485695.html

第10章 泛型算法

练习10.1

#include<iostream>
#include<algorithm>
#include<vector>using namespace std;int main() {int t, n;vector<int> vec;cout << "请输入序列个数：" << endl;cin >> n;cout << "请输入序列：" << endl;for (int i = 0;i < n;i++) {cin >> t;vec.push_back(t);}cout << "请输入要统计的值：" << endl;int num;cin >> num;cout << count(vec.begin(), vec.end(), num) << endl;system("pause");return 0;
}

练习10.2

#include<iostream>
#include<algorithm>
#include<list>
#include<string>using namespace std;int main() {int n;string t;list<string> lst;cout << "请输入字符串个数：" << endl;cin >> n;cout << "请输入" << n << "个字符串：" << endl;for (int i = 0;i < n;i++) {cin >> t;lst.push_back(t);}cout << "请输入要统计的字符串：" << endl;string num;cin >> num;cout << count(lst.begin(), lst.end(), num) << endl;system("pause");return 0;
}

练习10.3

#include<iostream>
#include<numeric>
#include<vector>using namespace std;int main() {vector<int> vec = { 1,2,3,4,5 };int sum = accumulate(vec.begin(), vec.end(), 0);cout << sum << endl;return 0;
}

练习10.4
初始值设为0表示返回值为int类型，会有精度损失

练习10.5
equal会比较指针地址，而不是字符串值，比较的结果与string类型的不一致。

练习10.6

fill_n(vec.begin(),vec.size(),0);

练习10.7
a.lst和vec之间的大小未保证相同，vec.resize(lst.size)
b.vec.resize(10);

练习10.9

#include<iostream>
#include<numeric>
#include<vector>
#include<algorithm>
#include<string>
using namespace std;void elimDups(vector<string> &words) {sort(words.begin(), words.end());auto end_unique = unique(words.begin(), words.end());cout << "unique后：";for (auto i : words) {cout << i << " ";}cout << endl;cout << "erase后：";words.erase(end_unique, words.end());for (auto i : words) {cout << i << " ";}cout << endl;
}int main() {vector<string> words = { "abc","abc","abc","bcd","efg","bcd","eqd" };elimDups(words);system("pause");return 0;
}

练习10.10
标准库算法对迭代器而不是容器进行操作。

练习10.11

#include<iostream>
#include<numeric>
#include<vector>
#include<algorithm>
#include<string>
using namespace std;bool isShorter(const string &s1, const string &s2) {return s1.size() < s2.size();
}void elimDups(vector<string> &words) {sort(words.begin(), words.end());auto end_unique = unique(words.begin(), words.end());words.erase(end_unique, words.end());
}int main() {vector<string> words = { "the","quick","red","fox","jumps","over","the","slow","red","turtle" };elimDups(words);stable_sort(words.begin(), words.end(), isShorter);for (auto &i : words) {cout << i << " ";}cout << endl;system("pause");return 0;
}

练习10.12

bool compareIsbn(const Sales_data &a, const Sales_data &b) {return a.isbn() < b.isbn();
}

练习10.13

#include<iostream>
#include<numeric>
#include<vector>
#include<algorithm>
#include<string>
using namespace std;bool cmp(const string &a) {return a.size() >= 5;
}int main() {vector<string> words = { "the","quick","red","fox","jumps","over","the","slow","red","turtle" };partition(words.begin(), words.end(), cmp);for (auto &i : words) {cout << i << " ";}cout << endl;system("pause");return 0;
}

练习10.14

#include<iostream>
using namespace std;
int main() {auto f = [](int a,int b) {return a + b;};cout << f(1, 2) << endl;return 0;
}

练习10.15

#include<iostream>
using namespace std;int main() {int a = 1;auto f = [a](int b) {return a + b;};cout << f(2) << endl;system("pause");return 0;
}

练习10.16

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>using namespace std;vector<string> &elimDups(vector<string> &words)
{sort(words.begin(), words.end());auto end_unique = unique(words.begin(), words.end());words.erase(end_unique, words.end());return words;
}void biggies(vector<string> &words, vector<string>::size_type sz)
{elimDups(words);stable_sort(words.begin(), words.end(),[](const string &a, const string &b){ return a.size() < b.size(); });auto wc = find_if(words.begin(), words.end(),[sz](const string &a){ return a.size() >= sz; });auto count = words.end() - wc;cout << count << endl;for(const auto s : words)cout << s << " ";cout << endl;
}int main()
{vector<string> vs = { "the","quick","red","fox","jumps","over","the","slow","red","turtle" };biggies(vs, 5);return 0;
}

练习 10.18-10.19

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>using namespace std;vector<string> &elimDups(vector<string> &words)
{sort(words.begin(), words.end());auto end_unique = unique(words.begin(), words.end());words.erase(end_unique, words.end());return words;
}void biggies(vector<string> &words, vector<string>::size_type sz)
{elimDups(words);auto wc = partition(words.begin(), words.end(),[sz](const string &a){ return a.size() >= sz; });//auto wc = stable_partition(words.begin(), words.end(),
//[sz](const string &a)
//{ return a.size() >= sz; });auto count = words.end() - wc;cout << count << endl;for (const auto s : words)cout << s << " ";cout << endl;
}int main()
{vector<string> vs = { "the","quick","red","fox","jumps","over","the","slow","red","turtle" };biggies(vs, 5);system("pause");return 0;
}

练习10.20

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>using namespace std;int main()
{vector<string> words = { "the","quick","red","fox","jumps","over","the","slow","red","turtle" };string::size_type sz = 6;auto wc = count_if(words.begin(), words.end(),[sz](const string &a){ return a.size() >= sz; });cout << wc << endl;system("pause");return 0;
}

练习10.21

#include<iostream>
#include<algorithm>using namespace std;int main() {int v = 5;auto f = [&v]()->bool{if (v <= 0) return false;else {--v;return true;}};while (f()) {cout << v << endl;}system("pause");return 0;
}

练习10.22

#include<iostream>
#include<algorithm>
#include<vector>
#include<string>
#include<functional>using namespace std;bool judge_size(string &s, string::size_type sz) {return s.size() >= sz;
}int main() {vector<string> words = { "the","quick","red","fox","jumps","over","the","slow","red","turtle" };cout << count_if(words.begin(), words.end(), bind(judge_size, placeholders::_1, 6)) << endl;system("pause");return 0;
}

练习10.23

假设要绑定的函数有n个参数，绑定取n + 1个参数。另外一个是函数本身的绑定。

练习10.24

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <functional>using namespace std;
bool check_size(string &s, int sz)
{return s.size() < sz;
}int main()
{vector<int> vi = { 1,2,3,4,5,6 };string s("aaaa");auto iter = find_if(vi.begin(), vi.end(), bind(check_size, s, placeholders::_1));cout << *iter << endl;system("pause");return 0;
}

练习10.25

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <functional>using namespace std;vector<string> &elimDups(vector<string> &words)
{sort(words.begin(), words.end());auto end_unique = unique(words.begin(), words.end());words.erase(end_unique, words.end());return words;
}bool check_size(const string &s, string::size_type sz)
{return s.size() >= sz;
}int main()
{vector<string> vs = { "the","quick","red","fox","jumps","over","the","slow","red","turtle" };auto iter = partition(vs.begin(), vs.end(), bind(check_size, placeholders::_1, 5));for (const auto s : vs)cout << s << " ";cout << endl;vs.erase(iter, vs.end());for (const auto s : vs)cout << s << " ";cout << endl;system("pause");return 0;
}

后续部分之后再更新。。