Codeforces Round #323 (Div. 2) C GCD Table 582A

#include<bits/stdc++.h>
using namespace std;

typedef int ll;

ll a[501];
int g[501*501];
ll gcd(ll a,ll b) { return b?gcd(b,a%b):a; }
map<int,int> mp;

//#define LOCAL
int main()
{
#ifdef LOCAL
    freopen("in.txt","r",stdin);
#endif
    int n; scanf("%d",&n);
    int sz = n*n;
    for(int i = 0; i < sz; i++){
        scanf("%d",g+i);
    }
    sort(g,g+sz,greater<int>());

    int c = 0,j = 0;
    a[c++] = g[j++];
    for(int i = 1; i < n; i++){
        while(j<sz && mp[g[j]]){
            mp[g[j]]--;
            j++;
        }
        if(j == sz) break;
        for(int k = c-1; k >= 0; k--){
            mp[gcd(a[k],g[j])] += 2;
        }
        a[c++] = g[j++];
    }
    while(c--){
        printf("%d",a[c]);
        if(c) putchar(‘ ‘);
    }
    return 0;
}