Submission #71434

#	Time	Username	Problem	Language	Result	Execution time	Memory
71434		someone_aa	Brunhilda’s Birthday (BOI13_brunhilda)	C++17	3.33 / 100	1115 ms	263168 KiB

brunhilda

#include <bits/stdc++.h>
#define ll long long
#define pb push_back
#define mp make_pair
using namespace std;
const int maxu = 10000100;
const int maxn = 100100;
bool prime[maxu], exist[maxu];
int primes[maxn], qi[maxn], dp[maxu], n, m, q;
int ind[maxn], tree[4*maxn], maxq, inf, maxx;
vector<int>p[maxu];

void sieve() {
    memset(prime,true,sizeof(prime));
    prime[0] = prime[1] = false;
    for(int i=2;i<maxx;i++) {
        if(prime[i]) {
            for(int j=i;j<maxx;j+=i) {
                if(exist[i])
                    p[j].pb(ind[i]);
                if(j > i) prime[j] = false;
            }
        }
    }
}

void update(int x, int val, int li=0, int ri=n-1, int index=1) {
    if(li==ri) tree[index] = val;
    else {
        int mid = (li+ri)/2;
        if(x <= mid) update(x,val,li,mid,2*index);
        else if(x>mid) update(x,val,mid+1,ri,2*index+1);
        tree[index] = min(tree[2*index], tree[2*index+1]);
    }
}

void solve() {
    inf = 1000000000;
    for(int i=1;i<=maxq;i++) {
        for(int j:p[i]) {
            update(j, inf);
        }
        dp[i] = tree[1] + 1;
        for(int j:p[i]) {
            update(j, dp[i]);
        }
    }
}


int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cin>>n>>q;
    for(int i=0;i<n;i++) {
        cin>>primes[i];
        exist[primes[i]] = true;
        ind[primes[i]] = i;
        maxx = max(maxx, primes[i] + 2);
    }

    sieve();
    for(int i=0;i<q;i++) {
        cin>>qi[i];
        maxq = max(maxq, qi[i]);
    }
    solve();
    for(int i=0;i<q;i++) {
        if(dp[qi[i]] >= inf) cout<<"oo\n";
        else cout<<dp[qi[i]]<<"\n";
    }

    return 0;
}

• Subtask 1: 3.3333333333333335 / 20
• Subtask 2: 0 / 20
• Subtask 3: 0 / 60