Submission #850325

#	Time	Username	Problem	Language	Result	Execution time	Memory
850325		TB_	Mag (COCI16_mag)	C++17	12 / 120	44 ms	13392 KiB

mag

#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(ll 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;

int seen[100001];
vvl adj(100001);
vl score;
ll longestOne = 1;
bool succes = false;

pl dp(int u, int last = -1){ // ones, parts
    pl res = {0, -1};
    for(auto &v : adj[u]){
        if(v == last) continue;
        pl val = dp(v, u);
        if(val.F == longestOne && score[u] == 2) {
            if(res.S == 0) succes = 1;
            res.S = 0;
        }
        if(score[u] == 1){
            if(val.F+res.S == longestOne-1 || val.S+res.F == longestOne-1) succes = 1;
            res.F = max(res.F, val.F);
            res.S = max(res.S, val.S);
        }
    }
    return {res.F+(score[u] == 1), res.S+(score[u] == 1)};
}

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

    ll n, from, to, pos, d;
    cin >> n;
    fo(i, n-1){
        cin >> from >> to;
        adj[--from].pb(--to);
        adj[to].pb(from);
    }
    score.resize(n);
    ll lowestFound = 1e18;
    fo(i, n) {
        cin >> score[i];
        lowestFound = min(lowestFound, score[i]);
    }
    if(lowestFound != 1) {
        cout << lowestFound << " " << 1;
        exit(0);
    }

    memset(seen, 0, sizeof(seen));
    fo(i, n){
        if(score[i] != 1 || seen[i]) continue;
        queue<pii> q;
        q.push(mp(i, 1));
        while(!q.empty()){
            tie(pos, d) = q.front(),
            q.pop();
            if(seen[pos]) continue;
            seen[pos] = 1;
            for(auto &v : adj[pos]) if(!seen[v] && score[v] == 1)q.push(mp(v, d+1));
        }
        q.push(mp(pos, 1));
        while(!q.empty()){
            tie(pos, d) = q.front(),
            q.pop();
            if(seen[pos] == 2) continue;
            seen[pos] = 2;
            for(auto &v : adj[pos]) if(seen[v] == 1 && score[v] == 1)q.push(mp(v, d+1));
        }
        longestOne = max(longestOne, d);
    }

    dp(0);
    if(succes) cout << "2/" << longestOne*2+1;
    else cout << "1/" << longestOne;

    return 0;
}

Compilation message (stderr)

mag.cpp: In function 'int main()':
mag.cpp:75:26: warning: 'd' may be used uninitialized in this function [-Wmaybe-uninitialized]
   75 |     ll n, from, to, pos, d;
      |                          ^

• Subtask 1: 0 / 12
• Subtask 2: 12 / 12
• Subtask 3: 0 / 12
• Subtask 4: 0 / 12
• Subtask 5: 0 / 12
• Subtask 6: 0 / 12
• Subtask 7: 0 / 12
• Subtask 8: 0 / 12
• Subtask 9: 0 / 12
• Subtask 10: 0 / 12