Submission #856675

#	Time	Username	Problem	Language	Result	Execution time	Memory
856675		efedmrlr	The Xana coup (BOI21_xanadu)	C++17	100 / 100	107 ms	25212 KiB

xanadu

#include <bits/stdc++.h>

using namespace std;

#define n_l '\n'
#define dbg(...) cout << "[" << #__VA_ARGS__ << "]: "; cout << to_string(__VA_ARGS__) << endl
template <typename T, size_t N> int SIZE(const T (&t)[N]){ return N; } template<typename T> int SIZE(const T &t){ return t.size(); } string to_string(const string s, int x1=0, int x2=1e9){ return '"' + ((x1 < s.size()) ? s.substr(x1, x2-x1+1) : "") + '"'; } string to_string(const char* s) { return to_string((string) s); } string to_string(const bool b) { return (b ? "true" : "false"); } string to_string(const char c){ return string({c}); } template<size_t N> string to_string(const bitset<N> &b, int x1=0, int x2=1e9){ string t = ""; for(int __iii__ = min(x1,SIZE(b)),  __jjj__ = min(x2, SIZE(b)-1); __iii__ <= __jjj__; ++__iii__){ t += b[__iii__] + '0'; } return '"' + t + '"'; } template <typename A, typename... C> string to_string(const A (&v), int x1=0, int x2=1e9, C... coords); int l_v_l_v_l = 0, t_a_b_s = 0; template <typename A, typename B> string to_string(const pair<A, B> &p) { l_v_l_v_l++; string res = "(" + to_string(p.first) + ", " + to_string(p.second) + ")"; l_v_l_v_l--; return res; } template <typename A, typename... C> string to_string(const A (&v), int x1, int x2, C... coords) { int rnk = rank<A>::value; string tab(t_a_b_s, ' '); string res = ""; bool first = true; if(l_v_l_v_l == 0) res += n_l; res += tab + "["; x1 = min(x1, SIZE(v)), x2 = min(x2, SIZE(v)); auto l = begin(v); advance(l, x1); auto r = l; advance(r, (x2-x1) + (x2 < SIZE(v))); for (auto e = l; e != r; e = next(e)) { if (!first) { res += ", "; } first = false; l_v_l_v_l++; if(e != l){ if(rnk > 1) { res += n_l; t_a_b_s = l_v_l_v_l; }; } else{ t_a_b_s = 0; } res += to_string(*e, coords...); l_v_l_v_l--; } res += "]"; if(l_v_l_v_l == 0) res += n_l; return res; } void dbgm(){;} template<typename Heads, typename... Tails> void dbgm(Heads H, Tails... T){ cout << to_string(H) << " | "; dbgm(T...); } 
#define dbgm(...) cout << "[" << #__VA_ARGS__ << "]: "; dbgm(__VA_ARGS__); cout << endl


#define int long long int
#define MP make_pair
#define pb push_back
#define REP(i,n) for(int (i) = 0; (i) < (n); (i)++)

void fastio() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
}


const double EPS = 0.00001;
const int INF = 1e9+500;
const int N = 3e5+5;
const int ALPH = 26;
const int LGN = 25;
const int MOD = 1e9+7;
int n,m,q;
vector<vector<int> > adj;
vector<int> a;
array<int,2> emparray = {0, 0};
array<array<int,2>, 2> dfs(int node, int par) {
    if(adj[node].size() <= 1) {
        array<array<int,2> , 2> ret;
        ret[a[node]][0] = 0;
        ret[a[node]][1] = INF;
        ret[!a[node]][0] = INF;
        ret[!a[node]][1] = 1;
        return ret;
    }
    array<array<int,2>, 2> lowerdp({emparray, emparray});
    lowerdp[0][1] = INF;
    lowerdp[1][1] = INF; 
    for(auto c : adj[node]) {
        if(c == par) continue;
        auto tmp = dfs(c, node);
        array<array<int,2> , 2> nwdp;
        for(int i = 0; i<2; i++) {
            nwdp[i][0] = min( lowerdp[i][0] + tmp[i][0], lowerdp[i][1] + tmp[i][1]);
            nwdp[i][1] = min(lowerdp[i][0] + tmp[i][1], lowerdp[i][1] + tmp[i][0] );
        }
        lowerdp = nwdp;
    }
    array<array<int,2> , 2> ret;
    ret[a[node]][0] = lowerdp[1][0];
    ret[a[node]][1] = lowerdp[0][1] + 1;
    ret[!a[node]][0] = lowerdp[1][1];
    ret[!a[node]][1] = lowerdp[0][0] + 1;
    return ret;
}

inline void solve() {
    cin>>n;
    adj.assign(n+1, vector<int>());
    a.resize(n+1);
    adj[1].pb(0);
    for(int i = 0; i<n-1; i++) {
        int u,v;
        cin>>u>>v;
        adj[u].pb(v);
        adj[v].pb(u);
    }
    for(int i = 1; i<=n; i++) {
        cin>>a[i];
        a[i] = !a[i];
    }

    auto ans = dfs(1, 0);
    int res = min(ans[1][0], ans[1][1]);
    if(res >= INF) cout<<"impossible\n";
    else cout<<res<<"\n";

}
 
signed main() {
    //fastio();
    int test = 1;
    //cin>>test;
    while(test--) {
        solve();
    }
    
}

Compilation message (stderr)

xanadu.cpp: In function 'std::string to_string(std::string, int, int)':
xanadu.cpp:7:208: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    7 | template <typename T, size_t N> int SIZE(const T (&t)[N]){ return N; } template<typename T> int SIZE(const T &t){ return t.size(); } string to_string(const string s, int x1=0, int x2=1e9){ return '"' + ((x1 < s.size()) ? s.substr(x1, x2-x1+1) : "") + '"'; } string to_string(const char* s) { return to_string((string) s); } string to_string(const bool b) { return (b ? "true" : "false"); } string to_string(const char c){ return string({c}); } template<size_t N> string to_string(const bitset<N> &b, int x1=0, int x2=1e9){ string t = ""; for(int __iii__ = min(x1,SIZE(b)),  __jjj__ = min(x2, SIZE(b)-1); __iii__ <= __jjj__; ++__iii__){ t += b[__iii__] + '0'; } return '"' + t + '"'; } template <typename A, typename... C> string to_string(const A (&v), int x1=0, int x2=1e9, C... coords); int l_v_l_v_l = 0, t_a_b_s = 0; template <typename A, typename B> string to_string(const pair<A, B> &p) { l_v_l_v_l++; string res = "(" + to_string(p.first) + ", " + to_string(p.second) + ")"; l_v_l_v_l--; return res; } template <typename A, typename... C> string to_string(const A (&v), int x1, int x2, C... coords) { int rnk = rank<A>::value; string tab(t_a_b_s, ' '); string res = ""; bool first = true; if(l_v_l_v_l == 0) res += n_l; res += tab + "["; x1 = min(x1, SIZE(v)), x2 = min(x2, SIZE(v)); auto l = begin(v); advance(l, x1); auto r = l; advance(r, (x2-x1) + (x2 < SIZE(v))); for (auto e = l; e != r; e = next(e)) { if (!first) { res += ", "; } first = false; l_v_l_v_l++; if(e != l){ if(rnk > 1) { res += n_l; t_a_b_s = l_v_l_v_l; }; } else{ t_a_b_s = 0; } res += to_string(*e, coords...); l_v_l_v_l--; } res += "]"; if(l_v_l_v_l == 0) res += n_l; return res; } void dbgm(){;} template<typename Heads, typename... Tails> void dbgm(Heads H, Tails... T){ cout << to_string(H) << " | "; dbgm(T...); }
      |                                                                                                                                                                                                             ~~~^~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 15 / 15
• Subtask 3: 10 / 10
• Subtask 4: 40 / 40
• Subtask 5: 30 / 30