#include <bits/stdc++.h>

using namespace std;

#define x first
#define y second

map<int, int> a;
map<pair<int, int>, int > b;
map<int, pair<int, int> > c;

int main()
{
	for (int i = 1; i <= 3; i ++ ) 
	{
		a[i] = i;
		b[{i, i}] = i + 3;
		c[i] = {i + 6, i + 6};
	}
	
	cout << 'a' << endl;//char型字符a
	for (auto p : a)
	{
		cout << p.x << ' ' << p.y << endl;//空格' '
	}
	
	cout << 'b' << endl;
	for (auto p : b)
	{
		cout << p.x.x << ' ' << p.x.y << ' ' << p.y << endl;
	}
	
	cout << 'c' << endl;
	for (auto p : c)
	{
		cout << p.x << ' ' << p.y.x << ' ' << p.y.y;
        puts("");//换行
	}
}

总结：用map读入的话，p.x, p.y,甚至p.x.x, p.x.y ,都行，换行可以endl 可以puts（""）;