37 lines
816 B
C++
37 lines
816 B
C++
#include <bits/stdc++.h>
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using namespace std;
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template <typename T>
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void print(vector<T> &v)
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{
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typename vector<T>::iterator it = v.begin();
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while (it != v.end())
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{
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cout << *it << " ";
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it++;
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}
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cout << endl;
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}
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int main()
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{
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int arr1[5] = {1, 2, 3, 4, 5};
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vector<double> v1(arr1, arr1 + 5);
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v1.resize(10, 9); // 重新指定容器的长度,并用9填充
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print(v1);
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vector<int> v2;
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v2.reserve(3); // 预留足够的空间避免频繁扩容导致的首地址变化
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// v2.resize(2); // resize 也可以预留空间，但是不会填充
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v2.push_back(1);
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cout << "first addr: " << &v2[0] << endl;
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v2.push_back(2);
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cout << "first addr: " << &v2[0] << endl;
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v2.push_back(3);
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cout << "first addr: " << &v2[0] << endl;
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return 0;
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}
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