C++Primer 习题3.6-3.20

string、vector的非迭代器用法

//3.6 #include<iostream> #include<string> using namespace std; int main() { for (char c : str1) { str2 += 'X'; } str1 = str2; cout << str1 << endl; //3.7 /* 如果改成char，结果相同 */ return 0; } //3.8 #include<iostream> #include<string> using namespace std; int main() { string str1{ "woshinibaba!" }; //string str2; for (int i = 0; i < str1.size(); i++) str1[i] = 'X'; cout << str1 << endl; string str2{ "woyeshinibaba!" }; int i = 0; while (i < str2.size()) { str2[i] = 'X'; i++; } cout << str2 << endl; i = 0; return 0; } //3.10 #include<iostream> #include<string> using namespace std; int main() { string str1 = { "A11!,)+_ b b" }; for (auto c : str1) if (!ispunct(c)) cout << c; return 0; } //3.11 #include<iostream> #include<string> using namespace std; int main() { const string str = "keep out"; for (auto a : str) { cout << a; } /* 这里VS2017可以通过。。。。 */ return 0; } //3.14 #include<iostream> #include<vector> using namespace std; int main() { vector<int> vint; for (int a; cin >> a;) { char f; vint.push_back(a); cout << "继续吗？F退出" << endl; cin >> f; if (f == 'F') break; } for (auto a : vint) cout << a << " "; return 0; } //3.15 #include<iostream> #include<vector> #include<string> using namespace std; int main() { vector<string> vint; for (string a; cin >> a;) { int f; vint.push_back(a); cout << "继续吗？1退出" << endl; cin >> f; if (f == 1) break; } for (auto a : vint) cout << a << " "; return 0; } //3.16 #include<iostream> #include<vector> using namespace std; int main() { vector<int> vint{ 1,2,33,444 }; cout << "容器大小为：" << vint.size() << endl; cout << "容器内元素为："; for (auto a : vint) cout << a << " "; return 0; } //3.17 /* 使用toupper(c); */ //3.18 /* ivec应当初始化，或者pushback一个元素等 */ //3.19 #include<iostream> #include<vector> using namespace std; int main() { vector<int> vint1{ 42,42,42,42,42,42,42,42,42,42 }; vector<int> vint2(10, 42); vector<int> vint3; for (int i = 0; i < 10; i++) { vint3.push_back(42); } for (auto a : vint1) cout << a << " "; cout << endl; for (auto a : vint2) cout << a << " "; cout << endl; for (auto a : vint3) cout << a << " "; cout << endl; //等等等等等 return 0; } //3.20 /* 还没想好如何终止输入的方便方法，程序简单不做赘述 */