intmain(){ mp1[43] =123; mp1[1] =1234; for(unordered_map<int,int>::iterator it = mp1.begin();it != mp1.end();it++){ cout<<it->first<<" "<<it->second<<endl; } return0; } STL 迭代器有的可以自减,有的不可以;比如 unordered_map 的迭代器是不可以自减的。
#include <string>#include<iostream>//查询性能最高//允许重复的,hash_map#include <unordered_map>#include<algorithm>usingnamespacestd;intmain() {//允许重复的映射unordered_map<string,double>mymap{ {"a1",113},{"a2",143},{"a3",1123} }; mymap.insert(pair<string,double>("a4",345));mymap...
+ 1 How to use easy search on unordered map Hi I have three field to be stored. For example, Id, name and last name but this three fields are available at different point of time during code execution. First of all, I have all id with me as input and available to me at one go...
// C++ program to illustrate// unordered_map::insert(iterator position1, iterator position2)#include<bits/stdc++.h>usingnamespacestd;intmain(){// initialize containerunordered_map<int,int> ump, ump1;//insertelements in random orderump.insert({2,20}); ump.insert({1,10}); ump.insert({...
// C++ program to illustrate // unordered_map::insert(iterator position, {key, element}) #include using namespace std; int main() { // initialize container unordered_map ump; // insert elements in random order ump.insert({ 'a', 1 }); ump.insert({ 'b', 2 }); auto it = ump....
map替换为map，要么在使用set_intersection之前创建临时map(或临时std::set<std::pair<int, int>>)。