Submission #955614

#	Time	Username	Problem	Language	Result	Execution time	Memory
955614		Neco_arc	Power Plant (JOI20_power)	C++17	0 / 100	2 ms	4956 KiB

power

#include <bits/stdc++.h>

#define ll long long
#define ull unsigned long long
#define all(x) x.begin(), x.end()
#define Neco "Power Plant"
#define resp(x) sort(all(x)), x.resize(unique(all(x)) - x.begin())
#define getbit(x,i) ((x >> i)&1)
#define _left id * 2, l, mid
#define _right id * 2 + 1, mid + 1, r
#define cntbit(x) __builtin_popcountll(x)
#define fi(i, a, b) for(int i = a; i <= b; i++)
#define fid(i, a, b) for(int i = a; i >= b; i--)
#define maxn (int) 2e5 + 7

using namespace std;

const ll mod = 1e9 + 7; //972663749
const ll base = 911382323;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

ll GetRandom(ll l, ll r)
{
    return uniform_int_distribution<ll> (l, r)(rng);
}

int n, res = 1;
int dp[maxn], cl[maxn];
vector<int> edges[maxn];

void dfs(int u, int par)
{
    vector<int> P;
    for(int v : edges[u]) if(v != par) {
        dfs(v, u);
        P.push_back(dp[v]);
    }

    sort(all(P), greater<int>());

    int ans = cl[u];
    int sum = 0;

    if(P.size() >= 1)
    {
        res = max(res, P[0] + cl[u]), ans = max(ans, P[0] + cl[u]);

        fi(i, 0, P.size() - 1) {
            sum += P[i];
            if(i > 1) res = max(res, sum), ans = max(ans, sum);
        }
        dp[u] = sum;
    }

    if(cl[u]) dp[u] = max(dp[u] - 1, 1);

//    cout << u << " " << dp[u] << " "  << ans << '\n';

}

void solve()
{

    cin >> n;

    fi(i, 1, n - 1) {
        int x, y;
        cin >> x >> y;
        edges[x].push_back(y), edges[y].push_back(x);
    }

    fi(i, 1, n) {
        char x; cin >> x;
        cl[i] = x - '0';
    }

    dfs(1, 0);
    cout << res;



}


int main()
{

    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    if(fopen(Neco".inp", "r")) {
        freopen(Neco".inp", "r", stdin);
        freopen(Neco".out", "w", stdout);
    }


    int nTest = 1;
//    cin >> nTest;


    while(nTest--)
    {
        solve();
    }


    return 0;
}

Compilation message (stderr)

power.cpp: In function 'void dfs(int, int)':
power.cpp:12:38: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   12 | #define fi(i, a, b) for(int i = a; i <= b; i++)
......
   49 |         fi(i, 0, P.size() - 1) {
      |            ~~~~~~~~~~~~~~~~~~         
power.cpp:49:9: note: in expansion of macro 'fi'
   49 |         fi(i, 0, P.size() - 1) {
      |         ^~
power.cpp: In function 'int main()':
power.cpp:94:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   94 |         freopen(Neco".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
power.cpp:95:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   95 |         freopen(Neco".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 6
• Subtask 2: 0 / 41
• Subtask 3: 0 / 53