第十二章 set和multiset

set和multiset插入，删除，查找都是O(log n)复杂度的。 set不允许重复 multiset则允许。

#include "iostream"#include "map"#include "set"using namespace std;int main() {multiset<int>st;int a[10] = { 1,14,12,13,7,13,21,19,8,8 };for (int i = 0; i < 10; i++) {st.insert(a[i]);}multiset<int>::iterator i;for (i = st.begin(); i != st.end(); i++) {cout << *i <<" ";}cout << endl;i = st.find(22);if (i == st.end()) {cout << "Not Found" << endl;}st.insert(22);i = st.find(22);if (i == st.end()) {cout << "Not Found" << endl;}else {cout << "Found" << endl;}i = st.lower_bound(13); // 返回最靠后的迭代器it [begin(),it)中的元素cout << *i << endl;i = st.upper_bound(8); //返回最靠前的迭代器it [it,end())中的元素都在8后面cout << *i << endl;st.erase(st.find(13));for (i = st.begin(); i != st.end(); i++) {cout << *i << " ";}cout << endl;return 0;}

/* 在vs2015中跑会出错 用在线编译器没问题 不知道为啥- -是支持的C++标准不一样么？*/#include <iostream>#include <functional>#include <set>using namespace std;struct Rule1 {bool operator()(const int & a, const int & b) {return (a % 10) < (b % 10);}//返回值为true则说明a必须排在b前面};int main() {multiset<int, greater<int> > st; //排序规则为从大到小int a[10] = { 1,14,12,13,7,13,21,19,8,8 };for (int i = 0; i < 10; ++i)st.insert(a[i]);multiset<int, greater<int> >::iterator i;for (i = st.begin(); i != st.end(); ++i)cout << *i << ",";cout << endl;multiset<int, Rule1 > st2;//st2的元素排序规则为：个位数小的排前面for (int i = 0; i < 10; ++i)st2.insert(a[i]);multiset<int, Rule1>::iterator p;for (p = st2.begin(); p != st2.end(); ++p)cout << *p << ",";cout << endl;p = st2.find(133); /* 能找到 因为不能确定是133排在13前面还是13排在133前面 所以即找到 输出13*/cout << *p << endl;return 0;}

/* 在vs2015中跑会出错 用在线编译器没问题 不知道为啥- -是支持的C++标准不一样么？*/#include <iostream>#include <functional>#include <set>using namespace std;struct Student {char name[20];int id;int score;};Student students[] = { { "Jack",112,78 },{ "Mary",102,85 },{ "Ala",333,92 },{ "Zero",101,70 },{ "Cindy",102,78 } };struct Rule {bool operator() (const Student& s1, const Student& s2) {if (s1.score != s2.score)return s1.score > s2.score;elsereturn (strcmp(s1.name, s2.name) < 0);}};int main() {multiset<Student, Rule>st;for (int i = 0; i < 5; i++) {st.insert(students[i]);}multiset<Student, Rule>::iterator p;for (p = st.begin(); p != st.end(); p++) {cout << p->score << " " << p->name << " " << p->id << endl;}Student s = { "Mary",1000,85 };p = st.find(s);if (p != st.end()) {cout << p->score << " " << p->name << " " << p->id << endl;}return 0;}

/* 在vs2015中跑会出错 用在线编译器没问题 不知道为啥- -是支持的C++标准不一样么？ */#include <iostream>#include <functional>#include <set>using namespace std;int main() {set<int>st;int a[10] = { 1,2,3,8,7,7,5,6,8,12 };for (int i = 0; i < 10; i++) {st.insert(a[i]);}cout << st.size() << endl;set<int>::iterator i;for (i = st.begin(); i != st.end(); i++) {cout << *i << " ";}cout << endl;pair<set<int>::iterator, bool>result = st.insert(2);if (!result.second) {cout << *result.first << " " << "already exist" << endl;}else {cout << *result.first << " " << "inserted" << endl;}return 0;}