map multimap
map,multimap key-value對容器，也叫字典，map中不能存放key相同的元素，而multimap可以，容器中元素默認按升序排序map multimap的相關操作
m.insert(map<T1,T2>::value_type(a1,a2));m.insert(make_pair(a1,a2));m.insert(pair<T1,T2>(a1,a2));a[a1]=a2; //multimap不能用這種方式m.find(val) //查找元素，返回迭代器m.erase(key) //通過key刪除元素m.erase(it) //通過迭代器刪除元素m.erase(it1,it2) //刪除迭代器范圍內的元素學習代碼
#include <iostream>#include <map>#include <string>using namespace std;int main(){ map<int, string> a; //鍵不能重復,默認按升序排序 multimap<int, string> ma; a.insert(map<int, string>::value_type(1, "One")); a.insert(map<int, string>::value_type(1, "one")); a.insert(map<int, string>::value_type(2, "Two")); a.insert(map<int, string>::value_type(3, "Three")); a.insert(make_pair(-1, "Minus One")); a.insert(pair<int, string>(1000, "One Thousand")); a[1000000] = "One Million";//multimap不能用這種方式 cout << "最簡單那的查找" << endl; cout << a[3] << endl; cout << "map里一共有" << a.size() << "個kye-value對數據" << endl; map<int, string>::const_iterator it = a.begin(); while (it != a.end()) { cout << "key" << it->first ; cout << " value" << it->second.c_str(); cout << endl; ++it; } ma.insert(multimap<int, string>::value_type(3, "Three")); ma.insert(multimap<int, string>::value_type(45, "Forty Five")); ma.insert(make_pair(-1, "Minus one")); ma.insert(pair<int, string>(1000, "One Thousand")); ma.insert(pair<int, string>(1000, "One Thousand")); multimap<int, string>::const_iterator itm = ma.begin(); while (itm != ma.end()) { cout << "key:" << itm->first; cout << " value:" << itm->second.c_str(); cout << endl; ++itm; } cout << "multimap里有" << ma.count(1000) << "個1000" << endl; multimap<int, string>::const_iterator fi; fi=ma.find(45); if (fi != ma.end()) { cout << "找到了" << fi->first<<" "<<fi->second.c_str()<< endl; } else { cout << "沒找到" << endl; } fi = ma.find(1000); if (fi != ma.end()) { cout << "找到了1000" << endl; size_t n = ma.count(1000); for (size_t i = 0; i < n; i++) { cout << "key:" << fi->first << "value:" << fi->second.c_str() << endl; ++fi; } } else { cout << "沒找到" << endl; } if (ma.erase(-1) > 0) cout << "刪除-1成功" << endl; multimap<int, string>::iterator itm2 = ma.find(45); if (itm2 != ma.end()) { ma.erase(itm2); cout << "刪除45成功" << endl; } ma.erase(ma.lower_bound(1000), ma.upper_bound(1000));//迭代器 getchar(); return 0;}新聞熱點
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