第三章 3.21

请使用迭代器重做3.3.3节的第一个练习

3.16：编写一段程序，把练习3.13中vector对象的容量和具体内容输出出来。

3.13

(a)vector<int> v1;

(b)vector<int> v2(10);

(c)vector<int> v3;(10,42);

(d)vector<int> v4{10};

(e)vector<int> v5{10,42};

(f)vector<string> v6{10};

(g)vector<string> v7{10,"hi"};

#include <iostream>#include <vector>#include <string>#include <cctype>using namespace std;int main(){               vector<int> v1;vector<int> v2(10);vector<int> v3;(10,42);vector<int> v4{10};vector<int> v5{10,42};vector<string> v6{10};vector<string> v7{10,"hi"};cout << "v1.size:" << v1.size() << endl;cout << "v2.size:" << v2.size() << endl;cout << "v3.size:" << v3.size() << endl;cout << "v4.size:" << v4.size() << endl;cout << "v5.size:" << v5.size() << endl;cout << "v6.size:" << v6.size() << endl;cout << "v7.size:" << v7.size() << endl;for(auto it = v1.begin(); it != v1.end(); ++it){cout << *it << " ";}cout << endl;for(auto it = v2.begin(); it != v2.end(); ++it){cout << *it << " ";}cout << endl;for(auto it = v3.begin(); it != v3.end(); ++it){cout << *it << " ";}cout << endl;for(auto it = v4.begin(); it != v4.end(); ++it){cout << *it << " ";}cout << endl;for(auto it = v5.begin(); it != v5.end(); ++it){cout << *it << " ";}cout << endl;for(auto it = v6.begin(); it != v6.end() && !it->empty(); ++it){cout << *it << " ";}cout << endl;for(auto it = v7.begin(); it != v7.end() && !it->empty(); ++it){cout << *it << " ";}return 0;}