Submission #294253

#	Time	Username	Problem	Language	Result	Execution time	Memory
294253		Denisov	Power Plant (JOI20_power)	C++14	100 / 100	210 ms	29752 KiB

power

#include <bits/stdc++.h>
#include <ext/rope>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("unroll-loops")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
//#define int long long
#define pb push_back
#define x first
#define y second
#define mk(a,b) make_pair(a,b)
#define rr return 0
#define sqr(a) ((a)*(a))
#define all(a) (a).begin(), (a).end()
#define sz(a) (int)(a).size()

using namespace std;
using namespace __gnu_cxx;
using namespace __gnu_pbds;

using ll = long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;

template<class value, class cmp = less<value> >
using ordered_set = tree<value, null_type, cmp, rb_tree_tag, tree_order_statistics_node_update>;
template<class value, class cmp = less_equal<value> >
using ordered_multiset = tree<value, null_type, cmp, rb_tree_tag, tree_order_statistics_node_update>;
template<class key, class value, class cmp = less<key> >
using ordered_map = tree<key, value, cmp, rb_tree_tag, tree_order_statistics_node_update>;

/// find_by_order()
/// order_of_key()
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
inline int randll(int l = INT_MIN, int r = INT_MAX) {
    return uniform_int_distribution<int>(l, r)(rng);
}
const int INF = 1e9, MOD = 1e9 + 7; /// think
const ll LINF = 1e18;


const int dx[] = {0, 0, 1, -1}, dy[] = {1, -1, 0, 0};
inline bool inside (int x, int y, int n, int m) {
    return 0 <= x && 0 <= y && x < n && y < m;
}

template<class T> bool umin (T &a, T b) {return a > b ? (a = b, true) : false; }
template<class T> bool umax (T &a, T b) {return a < b ? (a = b, true) : false; }

vector <vector <int> > edge;
string s;
vector <int> dp[2];
inline void dfs (int v, int p = -1) {
    dp[0][v] = s[v] == '1';
    dp[1][v] = 0;
    int sum = 0;
    for (int to : edge[v]) {
        if (to != p) {
            dfs(to, v);
            umax(dp[1][v], dp[1][to]);
            if (s[v] == '1') {
                umax(dp[1][v], dp[0][to] + 1);
            }
            sum += dp[0][to];
        }
    }
    umax(dp[0][v], sum - bool(s[v] == '1'));
}
main()
{
    ios::sync_with_stdio(0);
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int n;
    cin >> n;
    edge.resize(n);
    dp[0].resize(n);
    dp[1].resize(n);
    for (int i = 1, a, b; i < n; i++) {
        cin >> a >> b;
        --a, --b;
        edge[a].pb(b);
        edge[b].pb(a);
    }
    cin >> s;
    dfs(0);
    cout << max(dp[0][0], dp[1][0]) << '\n';
}

Compilation message (stderr)

power.cpp:71:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   71 | main()
      |      ^

• Subtask 1: 6 / 6
• Subtask 2: 41 / 41
• Subtask 3: 53 / 53