[英]Sorting a std::vector with elements of type pair<int, string>, but in reverse order
[英]Syntax to insert elements into multimap<string, vector<pair<string, int>>>
我的问题是如何将某些元素插入表单的多图
multimap<string, vector<pair<string, int>>> someMap; //std skipped to simplify
我尝试了不同的语法,我认为最接近的语法可能就是这个
someMap.insert(pair<string,vector<pair<string, int>>>(someString1, vector<pair<string, int>> { pair<string, int> (someString2, someInt) }));
不幸的是,它不起作用。 有小费吗??
第一对的类型是错误的
pair<string,vector<string, int>>
^^^^^^^^^^^
无论如何,我建议:
multimap<string, vector<pair<string, int>>> someMap;
vector<pair<string,int>> obj;
someMap.insert(make_pair("hello", obj));
或者,如果您坚持使用该语法(详细模式):
multimap<string, vector<pair<string, int>>> someMap;
string someString2 = "hello";
string someString1 = "world";
int someInt = 42;
someMap.insert(pair<string,vector<pair<string, int>>>(someString1, vector<pair<string, int>> { pair<string, int> (someString2, someInt) }));
这需要C ++ 11。
尝试以下
#include <iostream>
#include <map>
#include <vector>
#include <string>
#include <utility>
int main()
{
typedef std::pair<std::string, int> value_type;
std::multimap<std::string, std::vector<value_type>> m;
m.insert( { "A", std::vector<value_type>( 1, { "A", 'A' } ) } );
return 0;
}
或另一个例子
#include <iostream>
#include <map>
#include <vector>
#include <string>
#include <utility>
int main()
{
typedef std::pair<std::string, int> value_type;
std::multimap<std::string, std::vector<value_type>> m;
auto it = m.insert( { "A", std::vector<value_type>( 1, { "A", 'A' } ) } );
for ( char c = 'B'; c <= 'Z'; ++c )
{
const char s[] = { c, '\0' };
it->second.push_back( { s, c } );
}
size_t i = 0;
for ( const auto &p : it->second )
{
std::cout << "{" << p.first << ", " << p.second << "} ";
if ( ++i % 7 == 0 ) std::cout << std::endl;
}
std::cout << std::endl;
return 0;
}
输出是
{A, 65} {B, 66} {C, 67} {D, 68} {E, 69} {F, 70} {G, 71}
{H, 72} {I, 73} {J, 74} {K, 75} {L, 76} {M, 77} {N, 78}
{O, 79} {P, 80} {Q, 81} {R, 82} {S, 83} {T, 84} {U, 85}
{V, 86} {W, 87} {X, 88} {Y, 89} {Z, 90}
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