【题解】LuoGu1631：序列合并

原题传送门

• $a_1+b_1<=a_1+b_2<=...<=a_1+b_n$
• $a_2+b_1<=a_2+b_2<=...<=a_2+b_n$
• …
• $a_n+b_1<=a_n+b_2<=...<=a_n+b_n$

一开始先把$a_i+b_1$放进小根堆，每次取出最小的，比如$a_i+b_j$为当前最小，就输出后把$a_i+b_{j+1}$放进堆里

Code：

#include 
#define maxn 100010
using namespace std;
struct heap{
	int x, val;
	bool operator < (const heap &x) const {return x.val < val;}
};
priority_queue <heap> q;
int n, a[maxn], b[maxn], pos[maxn];

inline int read(){
	int s = 0, w = 1;
	char c = getchar();
	for (; !isdigit(c); c = getchar()) if (c == '-') w = -1;
	for (; isdigit(c); c = getchar()) s = (s << 1) + (s << 3) + (c ^ 48);
	return s * w;
}

int main(){
	n = read();
	for (int i = 1; i <= n; ++i) a[i] = read();
	for (int i = 1; i <= n; ++i) b[i] = read();
	for (int i = 1; i <= n; ++i) q.push((heap){i, a[i] + b[pos[i] = 1]});
	for (int i = 1; i <= n; ++i){
		heap tmp = q.top(); q.pop();
		printf("%d ", tmp.val);
		q.push((heap){tmp.x, a[tmp.x] + b[++pos[tmp.x]]});
	}
	return 0;
}