Submission #798450

#	Time	Username	Problem	Language	Result	Execution time	Memory
798450		TB_	Stranded Far From Home (BOI22_island)	C++17	100 / 100	195 ms	47384 KiB

island

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

// #undef _GLIBCXX_DEBUG                // disable run-time bound checking, etc
// #pragma GCC optimize("Ofast,inline") // Ofast = O3,fast-math,allow-store-data-races,no-protect-parens
// #pragma GCC optimize ("unroll-loops")

// #pragma GCC target("bmi,bmi2,lzcnt,popcnt")                      // bit manipulation
// #pragma GCC target("movbe")                                      // byte swap
// #pragma GCC target("aes,pclmul,rdrnd")                           // encryption
// #pragma GCC target("avx,avx2,f16c,fma,sse3,ssse3,sse4.1,sse4.2") // SIMD

// #include <bits/extc++.h>
// using namespace __gnu_pbds;
// template<class T>using ordered_set = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;
// template<class T>using ordered_multiset = tree<T, null_type, less_equal<T>, rb_tree_tag,tree_order_statistics_node_update>;

#define ll long long
#define INF (ll)1e9+7
#define fo(i, n) for(int i=0;i<((ll)n);i++)
#define deb(x) cout << #x << " = " << x << endl;
#define deb2(x, y) cout << #x << " = " << x << ", " << #y << " = " << y << endl
#define pb push_back
#define mp make_pair
#define F first
#define S second
#define LSOne(S) ((S) & (-S))
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
inline int readint(){ int v = 0; char c; while((c = getchar()) != EOF && c != ' ' && c != '\n'){ v *= 10; v += c - '0'; } return v; }
inline int readintsigned() { int v = 0; int sign = 1; char c = getchar(); if (c == '-') { sign = -1; } else { v += c - '0'; } while ((c = getchar()) != EOF && c != ' ' && c != '\n') { v *= 10; v += c - '0'; } return v * sign; }
inline string readstring() { string s; char c; while ((c = getchar()) != EOF && c != '\n' && c != ' ') { s.push_back(c); } return s; }
template <class result_t=std::chrono::milliseconds,class clock_t=std::chrono::steady_clock,class duration_t = std::chrono::milliseconds>
auto since(std::chrono::time_point<clock_t, duration_t> const& start){return std::chrono::duration_cast<result_t>(clock_t::now() - start);}
typedef pair<int, int> pii;
typedef pair<ll, ll> pl;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<pii> vpii;
typedef vector<pl> vpl;
typedef vector<vi> vvi;
typedef vector<vl> vvl;
typedef vector<vpii> vvpii;
typedef vector<vpl> vvpl;

ll n, m, val, from, to, w;
vl population;
vvl canAchieve;

vvl adj(200001);

struct UnionFind{
    int n;
    vl p, siz;
    UnionFind(int n) : n(n){
        p.assign(n, -1);
        siz.assign(n, 1);
        fo(i, n)p[i] = i;
    }

    int find(int x){
        if(p[x] == x) return x;
        return p[x] = find(p[x]);
    }

    void unite(int a, int b){
        a = find(a);
        b = find(b);
        if(siz[b] > siz[a]) {
            swap(a, b);
            swap(canAchieve[a], canAchieve[b]);
        }
        siz[a]+=siz[b];
        population[a]+=population[b];
        p[b] = a;
    }
};

int main() {
    // cout << fixed << setprecision(20);
    // auto start = std::chrono::steady_clock::now(); // since(start).count()
    cin.tie(0)->sync_with_stdio(0);

    cin >> n >> m;
    vpl popSort;
    fo(i, n){
        cin >> val;
        population.pb(val);
        popSort.pb({val, i});
        canAchieve.pb({i});
    }
    sort(all(popSort));
    pii biggestPop = popSort[n-1];


    fo(i, m){
        cin >> from >> to;
        adj[--from].pb(--to);
        adj[to].pb(from);
    }
    vi ans(n, 0);

    UnionFind uf(n);

    vi seen(n, 0);
    for(auto start : popSort){
        ll currentPop = population[start.S];
        for(auto v : adj[start.S]){
            if(!seen[v]) continue;
            from = uf.find(start.S);
            v = uf.find(v);
            if(from == v) continue;
            if(currentPop <= population[v]){
                if(canAchieve[from].size() < canAchieve[v].size()) swap(canAchieve[from], canAchieve[v]);
                fo(i, canAchieve[v].size()) canAchieve[from].pb(canAchieve[v][i]);
            }
            uf.unite(from, v);
        }
        seen[start.S] = 1;   
    }
    fo(i, canAchieve[uf.find(biggestPop.S)].size()) ans[canAchieve[uf.find(biggestPop.S)][i]] = 1;
    fo(i, n) cout << ans[i];

    return 0;
}

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