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답안 #379815

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
379815 2021-03-19T11:09:02 Z Vimmer Svjetlo (COCI20_svjetlo) C++14
110 / 110
 449 ms 77300 KB 
#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>

//#pragma GCC optimize("unroll-loops")
//#pragma GCC optimize("-O3")
//#pragma GCC optimize("Ofast")

#define N 500500
#define NN 10000050
#define PB push_back
#define M ll(1e9 + 7)
#define all(x) x.begin(), x.end()
#define sz(x) int(x.size())
#define pri(x) cout << x << endl
#define endl '\n'
#define _ << " " <<
#define F first
#define S second

using namespace std;
//using namespace __gnu_pbds;

typedef long long ll;
//typedef tree <ll, null_type, less_equal <ll>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;

typedef long double ld;
typedef unsigned long long ull;
typedef short int si;

vector <int> g[N];

string s;

int f[N][2][3], n;

int dp[2][3];

void solve_0(int v, int u)
{
    for (int cur = 0; cur < 2; cur++)
    {
        /// he 0
        dp[cur][0] = min(dp[cur][0], f[v][cur][0] + f[u][0][0] + 3);

        /// he 1
        dp[cur ^ 1][0] = min(dp[cur ^ 1][0], f[v][cur][0] + f[u][1][0] + 1);
    }
}

void solve_1(int v, int u)
{
    for (int cur = 0; cur < 2; cur++)
    {
        dp[cur][1] = min(dp[cur][1], f[v][cur][1] + f[u][0][0] + 3);

        dp[cur ^ 1][1] = min(dp[cur ^ 1][1], f[v][cur][1] + f[u][1][0] + 1);

        dp[cur][1] = min(dp[cur][1], f[v][cur][0] + min(f[u][1][0], f[u][1][1]));
        dp[cur ^ 1][1] = min(dp[cur ^ 1][1], f[v][cur][0] + min(f[u][0][0], f[u][0][1]) + 2);
    }
}

void solve_2(int v, int u)
{
    for (int cur = 0; cur < 2; cur++)
    {
        dp[cur][2] = min(dp[cur][2], f[v][cur][2] + f[u][0][0] + 3);
        dp[cur ^ 1][2] = min(dp[cur ^ 1][2], f[v][cur][2] + f[u][1][0] + 1);

        dp[cur][2] = min(dp[cur][2], f[v][cur][0] + min(min(f[u][0][1], f[u][0][0]), f[u][0][2]) + 1);
        dp[cur ^ 1][2] = min(dp[cur ^ 1][2], f[v][cur][0] + min(min(f[u][1][0], f[u][1][1]), f[u][1][2]) + 3);

        dp[cur][2] = min(dp[cur][2], f[v][cur][1] + min(f[u][1][1], f[u][1][0]));
        dp[cur ^ 1][2] = min(dp[cur ^ 1][2], f[v][cur][1] + min(f[u][0][1], f[u][0][0]) + 2);
    }
}

void dfs(int v, int p)
{
    bool have = 0;

    for (auto it : g[v])
    {
        if (it == p) continue;

        dfs(it, v);

        if (f[it][1][0] == 0) continue;

        have = 1;
    }

    if (!have && s[v] == '1')
    {
        f[v][1][0] = 0;

        return;
    }

    f[v][!(s[v] == '1')][0] = 1;

    for (auto it : g[v])
    {
        if (it == p || f[it][1][0] == 0) continue;

        for (int i = 0; i < 2; i++)
            for (int j = 0; j < 3; j++)
                dp[i][j] = 1e9;

        solve_0(v, it);
        solve_1(v, it);
        solve_2(v, it);

        for (int i = 0; i < 2; i++)
            for (int j = 0; j < 3; j++)
                f[v][i][j] = dp[i][j];
    }
}

int main()
{
    ios_base::sync_with_stdio(0); istream::sync_with_stdio(0); cin.tie(0); cout.tie(0);

//    freopen("1.in", "r", stdin);

    for (int i = 0; i < N; i++)
        for (int t = 0; t < 2; t++)
            for (int l = 0; l < 3; l++)
                f[i][t][l] = 1e9;

    cin >> n;

    cin >> s;

    for (int i = 1; i < n; i++)
    {
        int x, y;

        cin >> x >> y;

        x--; y--;

        g[x].PB(y);

        g[y].PB(x);
    }

    for (int i = 0; i < n; i++)
    {
        if (s[i] == '1') continue;

        dfs(i, -1);

        pri(min(min(f[i][1][0], f[i][1][1]), f[i][1][2]));

        exit(0);
    }

    pri(0);
}

Subtask #1
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 15 ms 23788 KB Output is correct
2 Correct 16 ms 23788 KB Output is correct
3 Correct 16 ms 23788 KB Output is correct
4 Correct 16 ms 23788 KB Output is correct
5 Correct 16 ms 23788 KB Output is correct
6 Correct 16 ms 23788 KB Output is correct
7 Correct 15 ms 23788 KB Output is correct
8 Correct 15 ms 23788 KB Output is correct
9 Correct 18 ms 23788 KB Output is correct

Subtask #2
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 266 ms 55592 KB Output is correct
2 Correct 402 ms 72832 KB Output is correct
3 Correct 409 ms 77300 KB Output is correct
4 Correct 344 ms 57856 KB Output is correct
5 Correct 400 ms 64512 KB Output is correct

Subtask #3
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 324 ms 36608 KB Output is correct
2 Correct 449 ms 39884 KB Output is correct
3 Correct 417 ms 39936 KB Output is correct
4 Correct 309 ms 37376 KB Output is correct
5 Correct 301 ms 40448 KB Output is correct
6 Correct 268 ms 38656 KB Output is correct
7 Correct 333 ms 40692 KB Output is correct

Subtask #4
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 15 ms 23788 KB Output is correct
2 Correct 16 ms 23788 KB Output is correct
3 Correct 16 ms 23788 KB Output is correct
4 Correct 16 ms 23788 KB Output is correct
5 Correct 16 ms 23788 KB Output is correct
6 Correct 16 ms 23788 KB Output is correct
7 Correct 15 ms 23788 KB Output is correct
8 Correct 15 ms 23788 KB Output is correct
9 Correct 18 ms 23788 KB Output is correct
10 Correct 266 ms 55592 KB Output is correct
11 Correct 402 ms 72832 KB Output is correct
12 Correct 409 ms 77300 KB Output is correct
13 Correct 344 ms 57856 KB Output is correct
14 Correct 400 ms 64512 KB Output is correct
15 Correct 324 ms 36608 KB Output is correct
16 Correct 449 ms 39884 KB Output is correct
17 Correct 417 ms 39936 KB Output is correct
18 Correct 309 ms 37376 KB Output is correct
19 Correct 301 ms 40448 KB Output is correct
20 Correct 268 ms 38656 KB Output is correct
21 Correct 333 ms 40692 KB Output is correct
22 Correct 353 ms 37920 KB Output is correct
23 Correct 376 ms 38656 KB Output is correct
24 Correct 337 ms 38016 KB Output is correct
25 Correct 355 ms 37420 KB Output is correct
26 Correct 318 ms 41856 KB Output is correct
27 Correct 315 ms 41472 KB Output is correct
28 Correct 248 ms 39040 KB Output is correct
29 Correct 301 ms 40700 KB Output is correct
30 Correct 303 ms 39284 KB Output is correct