Leha like all kinds of strange things. Recently he liked the function F(n, k). Consider all possible k-element subsets of the set [1, 2, ..., n]. For subset find minimal element in it. F(n, k) — mathematical expectation of the minimal element among all k-element subsets.
But only function does not interest him. He wants to do interesting things with it. Mom brought him two arrays A and B, each consists of m integers. For all i, j such that 1 ≤ i, j ≤ m the condition Ai ≥ Bj holds. Help Leha rearrange the numbers in the array A so that the sum is maximally possible, where A' is already rearranged array.
First line of input data contains single integer m (1 ≤ m ≤ 2·105) — length of arrays A and B.
Next line contains m integers a1, a2, ..., am (1 ≤ ai ≤ 109) — array A.
Next line contains m integers b1, b2, ..., bm (1 ≤ bi ≤ 109) — array B.
Output m integers a'1, a'2, ..., a'm — array A' which is permutation of the array A.
5
7 3 5 3 4
2 1 3 2 3
4 7 3 5 3
7
4 6 5 8 8 2 6
2 1 2 2 1 1 2
2 6 4 5 8 8 6
题意:给出a、b两个数组,a数组任意一个数都大于b数组的任意一个数,将a数组重新排列使得 最大
思路:题目有给出提示:定义F(n,k):F(n, k)是在集合{1, 2, 3, ..., n}中所有的具有k个元素的子集中分别取最小值,相加后的期望
。For example, let's find F(4, 2). All possible 2-element subsets of {1,2,3,4} are: {1, 2}, {1, 3}, {1, 4}, {2, 3}, {2, 4}, {3, 4}. Their minimal values are 1, 1, 1, 2, 2, 3. So the average (expected) value is F(4,2)=(1+1+1+2+2+3)/6=10/6=1.66666666
可得两个结论:
F(n,k)>F(nm,k) n>m
F(n,k)>F(n,p) k<p
所以a中最小的数对应b中最大的数,依次递推
code:
#include<stdio.h>
#include<algorithm>
using namespace std;
int a[200005],b[200005];
struct node{
int x,pos;
}q[200005];
int cmp(node t1,node t2){
return t1.x>t2.x;
}
int main(){
int n,i;
while(~scanf("%d",&n)){
for(i=0;i<n;i++) scanf("%d",&a[i]);
for(i=0;i<n;i++){
scanf("%d",&q[i].x);
q[i].pos=i;
}
sort(a,a+n);
sort(q,q+n,cmp);
for(i=0;i<n;i++){
b[q[i].pos]=a[i];
}
for(i=0;i<n;i++) printf("%d%c",b[i],i==n?'\n':' ');
}
return 0;
}