【小米oj】 不一样的排序

线性筛+sort

#define mm(a) memset(a,0,sizeof(a));
#define max(x,y) (x)>(y)?(x):(y)
#define min(x,y) (x)<(y)?(x):(y)
#define Fopen freopen("1.in","r",stdin); freopen("m.out","w",stdout);
#define rep(i,a,b) for(int i=(a);i<=(b);i++)
#define per(i,b,a) for(int i=(b);i>=(a);i--)
#include<bits/stdc++.h>
typedef long long ll;
#define PII pair<ll,ll>
using namespace std;
const int INF=0x3f3f3f3f;
const int MAXN=(int)2e6 + 5;

struct node
{
    int x;
    int id;
    int val;
}a[MAXN];
bool vis[MAXN];
int prime[MAXN];

int t[MAXN],e[MAXN],n,k;
//geshu  fuzhu
void Init() {
    int cnt=0;
    t[1]=1;
    for(int i=2; i<=MAXN; ++i) {
        if(!vis[i]) {
            prime[++cnt]=i;
            t[i]=2;
            e[i]=1;
        }
        for(int j=1; j<=cnt; ++j) {
            if(i*prime[j]>MAXN) break;
            vis[i*prime[j]]=true;
            if(i%prime[j]==0) {
                t[i*prime[j]]=t[i]/(e[i]+1)*(e[i]+2);
                e[i*prime[j]]=e[i]+1;
                break;
            } else {
                t[i*prime[j]]=t[i]*2;
                e[i*prime[j]]=1;
            }
        }
    }
}


int main() {
    Init();
    while(~scanf("%d%d",&k,&n)) {
        for(int i=1;i<=n;i++)scanf("%d",&a[i].x),a[i].id=i,a[i].val=t[a[i].x];
        sort(a+1,a+1+n,[](node a,node b){
            if(a.val!=b.val)return a.val<b.val;
            return a.x<b.x;
        });
        printf("%d
",a[k].x);
    }
    return 0;
}