k-th number pair
大致题意:给你n个数a[1],a[2],......,a[n],总共有n^2对(a[i],a[j]),1<=i<=j<=n,问你第k对,输出他。
本身不是很难,但开始大家都狂wa,数可能有相同的,所以得另外考虑
贴上代码:
#include <iostream>
#include <cstdio>
#include<algorithm>
#include<cstring>
#include<queue>
#define INF 2000000000
#define max(a,b) (a)>(b)?(a):(b)
#define read(a) scanf("%d",&a);
using namespace std;
const int maxn = 100005;
int a[maxn];
int main()
{
int n,k;
while(scanf("%d%d",&n,&k)==2){
for(int j=0;j<n;j++)read(a[j])
sort(a,a+n);
int pos=(k-1)/n,i,cnt=0,t,t1;
for(i=pos;i>=0&&a[i]==a[pos];i--);t=i+1;
for(i=pos;i<n&&a[i]==a[pos];i++);t1=i;
k-=t*n;
printf("%d %d\n",a[pos],a[(k-1)/(t1-t)]);
}
return 0;
}