3.4.1

来源：互联网发布：java udp编程和 tcp 编辑：程序博客网时间：2024/06/08 13:56

3.21

#include<iostream>#include<string>#include<vector>using namespace std;void print(const vector<int> & vec) {    cout << vec.size() << endl;    for (auto a = vec.begin(); a != vec.end(); ++a) {        cout << *a << " ";    }    cout << endl;}void print(const vector<string> & vec) {    cout << vec.size() << endl;    for (auto a = vec.begin(); a != vec.end(); ++a) {        cout << *a << " ";    }    cout << endl;}int main() {    vector<int> v1;                     // size:0,  no values.    vector<int> v2(10);                 // size:10, value:0    vector<int> v3(10, 42);             // size:10, value:42    vector<int> v4{ 10 };               // size:1,  value:10    vector<int> v5{ 10, 42 };           // size:2,  value:10, 42    vector<string> v6{ 10 };            // size:10, value:""    vector<string> v7{ 10, "hi" };      // size:10, value:"hi"\    print(v1);    print(v2);    print(v3);    print(v4);    print(v5);    print(v6);    print(v7);    return 0;}

3.22

#include<iostream>#include<string>#include<vector>using namespace std;int main() {    string buffer;    vector<string> vec;    while (cin >> buffer) {        vec.push_back(buffer);    }    for (auto &a : vec) {        for (auto &b : a) {            b= toupper(b);        }        cout << a << " ";    }    cout << endl;    return 0;}

3.23

#include<vector>#include<iostream>using namespace std;int main() {    vector<int> vec{ 0,10,20,30,40,50,60,70,80,90 };    for (auto i = vec.begin(); i != vec.end(); ++i) {        *i *= 2;    }    for (auto a : vec) {        cout << a << " ";    }    return 0;}

0 0