如何在C ++中初始化向量?
初始化向量可以通过多种方式完成
1)通过push_back()方法初始化向量
算法
Begin Declare v of vector type. Call push_back() function to insert values into vector v. Print “向量元素:”. for (int a : v) print all the elements of variable a. End.
示例
#include<iostream> #include <bits/stdc++.h> using namespace std; int main() { vector<int> v; v.push_back(6); v.push_back(7); v.push_back(10); v.push_back(12); cout<<"向量元素:"<<endl; for (int a : v) cout << a << " "; return 0; }
输出结果
向量元素: 6 7 10 12
2)通过数组初始化向量
算法
Begin Create a vector v. Initialize vector like array. Print the elements. End.
示例
#include <bits/stdc++.h> using namespace std; int main() { vector<int> v{ 1, 2, 3, 4, 5, 6, 7 }; cout<<"向量元素:"<<endl; for (int a : v) cout << a << " "; return 0; }
输出结果
向量元素: 1 2 3 4 5 6 7
3)从另一个向量初始化一个向量
算法
Begin Create a vector v1. Initialize vector v1 by array. Initialize vector v2 by v1. Print the elements. End.
示例
#include<iostream> #include <bits/stdc++.h> using namespace std; int main() { vector<int> v1{ 1, 2, 3, 4, 5, 6, 7 }; vector<int> v2(v1.begin(), v1.end()); cout<<"向量元素:"<<endl; for (int a : v2) cout << a << " "; return 0; }
输出结果
向量元素: 1 2 3 4 5 6 7
4)通过指定大小和元素来初始化向量
算法
Begin Initialize a variable s. Create a vector v with size s and all values with 7. Initialize vector v1 by array. Initialize vector v2 by v1. Print the elements. End.
示例
#include<iostream> #include <bits/stdc++.h> using namespace std; int main() { int s= 5; vector<int> v(s, 7); cout<<"向量元素:"<<endl; for (int a : v) cout << a << " "; return 0; }
输出结果
向量元素: 7 7 7 7 7