[P1631] sequences into Luo Gu heap []

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Subject to the effect:

Topic links: https://www.luogu.org/problemnew/show/P1631
There are two lengths $n$ sequences $a$ and $b$ , in $a$ and $b$ the sum can be obtained from each of a number $n^2$ Ge and, asked this $n^2$ th smallest and $n$ a.

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Digression:

$\color{red}\texttt{AC500祭}$

I accuracy rate is really low qwq

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Ideas:

As the title says $a,b$ are monotonically increasing. So we can not consider the sort.
Monotonically increasing at the same time meet the special
$a[x]+b[1]<a[x]+b[2]<...<a[x]+a[n](x\in [1,n])$

So every time we just maintenance $n$ minimum value can be a number (respectively $a[1]+b[k_1],a[2]+b[k_2],...,a[n]+b[k_n]$ , Which $k_i$Show $i$ 've accomplished maintained $b$ Array Pointer)
for the minimum may be considered to maintain a small heap root. Each element maintain a triple $(val,x,k)$ , indicates that this $a[x]+b[k]$ value.
in case $(val_i,x_i,k_i)$ Is the minimum heap, then the output $val_i$Pop-up, and insert $(a[x_i]+b[k_i+1],x_i,k_i+1)$ .
do $n$ times the above-described method may be.
time complexity $O(n\log n)$

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Code:

#include <queue>
#include <cstdio>
#define mp make_pair
using namespace std;

const int N=100010;
int n,a[N],b[N];
priority_queue<pair<int,pair<int,int> > > q;  //pair套pair最为致命（三元组）

int main()
{
	scanf("%d",&n);
	for (int i=1;i<=n;i++)
		scanf("%d",&a[i]);
	for (int i=1;i<=n;i++)
		scanf("%d",&b[i]);
	for (int i=1;i<=n;i++)
		q.push(mp(-a[i]-b[1],mp(i,1)));  //插入初始值
	for (int i=1;i<=n;i++)
	{
		printf("%d ",-q.top().first);
		int x=q.top().second.first,y=q.top().second.second;
		q.pop();
		q.push(mp(-a[x]-b[y+1],mp(x,y+1)));
	}
	return 0;
}