题解 | #kotori和素因子#

#include <iostream>
#include <algorithm>
#include <cmath>
#include <vector>

using namespace std;

const int maxn = 1e3 + 5;
const int INF = 0x3f3f3f3f;
vector <int> e[maxn];
int m, n, x,sum,minS;
bool vis[maxn], flag;


bool fun(int k) {// 是否为素数
    if (k == 1) return false;
    for (int i = 2; i <= floor(sqrt(k)); i++) {
        if (k % i == 0)
            return false;
    }
    return true;
}

void prime(int k,int x) {//存数
    for (int i = 1; i <= floor(sqrt(k)); i++) {
        if (k % i == 0) {
            if (fun(i))
                e[x].push_back(i);
            if (i * i != k && fun(k / i))
                e[x].push_back(k / i);
        }    
    }
}

void dfs(int y) {
    if (y == x) {
        minS = min(minS, sum);
        flag = 1;
        return;
    }
    for (int i = 0; i < e[y].size(); i++) {
        if (!vis[e[y][i]]) {
            sum += e[y][i];
            vis[e[y][i]] = 1;
            dfs(y + 1);
            sum -= e[y][i];
            vis[e[y][i]] = 0;
        }
    }
}

int main() {
    cin >> n;
    for (int i = 0; i < n; i++) {
        cin >> m;
        prime(m,x++);
    }
    minS = INF;
    dfs(0);
    if (flag == 1) {
        cout << minS;
    }
    else
        cout << -1;
    return 0;
}