Submission #804951

#	Time	Username	Problem	Language	Result	Execution time	Memory
804951		Khizri	Stranded Far From Home (BOI22_island)	C++17	100 / 100	240 ms	38384 KiB

island

#pragma GCC optimize ("O3")
#include <bits/stdc++.h>
using namespace std;
//------------------------------DEFINE------------------------------
//******************************************************************
#define IOS ios_base::sync_with_stdio(false); cin.tie(0),cout.tie(0)
#define ll long long
#define pb push_back
#define F first
#define S second
#define INF 1e18
#define all(v) (v).begin(),(v).end()
#define rall(v) (v).rbegin(),(v).rend()
#define pii pair<int,int>
#define pll pair<ll,ll>
#define OK cout<<"Ok"<<endl;
#define MOD (ll)(1e9+7)
#define endl "\n"
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
//******************************************************************
//----------------------------FUNCTION------------------------------
//******************************************************************
ll gcd(ll a,ll b){
    if(a>b) swap(a,b);
    if(a==0) return a+b;
    return gcd(b%a,a);
}
ll lcm(ll a,ll b){
    return a/gcd(a,b)*b;
}
bool is_prime(ll n){
    ll k=sqrt(n);

    if(n==2) return true;
    if(n<2||n%2==0||k*k==n) return false;
    for(int i=3;i<=k;i+=2){
        if(n%i==0){
            return false;
        }
    }
    return true;
}
//*****************************************************************
//--------------------------MAIN-CODE------------------------------
const int mxn=2e5+5;
ll t=1,n,m,arr[mxn],p[mxn],sum[mxn],ans[mxn];
vector<int>vt[mxn];
vector<int>good[mxn];
int fnd(int u){
    if(p[u]==u) return u;
    return p[u]=fnd(p[u]);
}
void Union(int u,int v){
    u=fnd(u);
    v=fnd(v);
    if(u!=v){
        if(good[v].size()>good[u].size()) swap(u,v);
        sum[u]+=sum[v];
        p[v]=u;
        for(int x:good[v]){
            good[u].pb(x);
        }
    }
}
bool cmp(int x,int y){
    return arr[x]<arr[y];
}
void solve(){
    cin>>n>>m;
    for(int i=1;i<=n;i++){
        cin>>arr[i];
    }
    for(int i=1;i<=m;i++){
        int x,y;
        cin>>x>>y;
        vt[x].pb(y);
        vt[y].pb(x);
    }
    for(int i=1;i<=n;i++){
        sort(all(vt[i]),cmp);
        p[i]=i;
        sum[i]=arr[i];
        good[i].pb(i);
    }
    vector<int>idx(n);
    iota(all(idx),1);
    sort(all(idx),cmp);
    for(int i=0;i<idx.size();i++){
        int u=idx[i];
        for(int v:vt[u]){
            if(arr[v]>arr[u]) break;
            if(sum[fnd(v)]<arr[u]){
                good[fnd(v)].clear();
            }
            Union(u,v);
        }
    }
    int node=idx.back();
    for(int x:good[fnd(node)]){
        ans[x]=1;
    }
    for(int i=1;i<=n;i++){
        cout<<ans[i];
    }
    cout<<endl;
}
int main(){
    IOS;
    //cin>>t;
    while(t--){
        solve();
    }
    return 0;
}

Compilation message (stderr)

island.cpp: In function 'void solve()':
island.cpp:88:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   88 |     for(int i=0;i<idx.size();i++){
      |                 ~^~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 15 / 15
• Subtask 4: 30 / 30
• Subtask 5: 35 / 35