admin管理员组

文章数量:1612061

vector<int> ivec;
cout << "大小：" << ivec.size() << ",容量" << ivec.capacity() << endl;//0,0
ivec.push_back(10);
cout << "大小：" << ivec.size() << ",容量" << ivec.capacity() << endl;//1,1
ivec.push_back(20);
cout << "大小：" << ivec.size() << ",容量" << ivec.capacity() << endl;//2,2
ivec.push_back(30);
cout << "大小：" << ivec.size() << ",容量"<<ivec.capacity() << endl;//3,3
ivec.push_back(40);
cout << "大小：" << ivec.size() << ",容量" << ivec.capacity() << endl;//4,4
ivec.push_back(50);
cout << "大小：" << ivec.size() << ",容量" << ivec.capacity() << endl;//5,5
ivec.push_back(60);
cout << "大小：" << ivec.size() << ",容量" << ivec.capacity() << endl;//6,6
ivec.push_back(70);
cout << "大小：" << ivec.size() << ",容量" << ivec.capacity() << endl;//7,9
ivec.push_back(80);
cout << "大小：" << ivec.size() << ",容量" << ivec.capacity() << endl;//8,9
ivec.push_back(40);
cout << "大小：" << ivec.size() << ",容量" << ivec.capacity() << endl;//9,9
ivec.push_back(40);
cout << "大小：" << ivec.size() << ",容量" << ivec.capacity() << endl;//10,13
ivec.push_back(1);
ivec.push_back(1);
ivec.push_back(1);
cout << "大小：" << ivec.size() << ",容量" << ivec.capacity() << endl;//13,13
ivec.push_back(1);
cout << "大小：" << ivec.size() << ",容量" << ivec.capacity() << endl;//14,19

capacity() 和size()区别：
size()为容器实际元素的个数
capacity()为容器目前所能容纳的最大元素个数，一旦容量不够了，就会重新分配一段连续的比原有空间大的内存大小，将原来的元素拷贝到新的容器空间内，继续添加，每一次容量的增长50%

reserve(n)
按需申请n个大小的容量，此时容量capacity就变为n

本文标签： VectorCapacityreserve

版权声明：本文标题：vector中capacity,reserve 内容由热心网友自发贡献，该文观点仅代表作者本人， 转载请联系作者并注明出处：https://www.elefans.com/xitong/1728621750a1166443.html， 本站仅提供信息存储空间服务，不拥有所有权，不承担相关法律责任。如发现本站有涉嫌抄袭侵权/违法违规的内容，一经查实，本站将立刻删除。