Submission #1253344

#	Time	Username	Problem	Language	Result	Execution time	Memory
1253344		CodeLakVN	Mergers (JOI19_mergers)	C++20	0 / 100	30 ms	17084 KiB

mergers

#include <bits/stdc++.h>
using namespace std;

#define task "main"
#define F first
#define S second
#define ii pair<int, int>
#define il pair<int, long long>
#define li pair<long long, int>
#define FOR(i, a, b) for(int i = (a); i <= (b); ++i)
#define FOD(i, b, a) for(int i = (b); i >= (a); --i)

template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b) {a = b; return true;}
        return false;
    }

template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b) {a = b; return true;}
        return false;
    }

template <class T>
    void printArr(T container, string separator = " ", string finish = "\n", ostream &out = cout){
        for(auto item: container) out << item << separator;
        out << finish;
    }

const int MAX_N = (int)5e5 + 4;

int nNode, nColor;
vector<int> adj[MAX_N];
int color[MAX_N];

int total[MAX_N], cnt[MAX_N];
int sz[MAX_N];

void DFS_size(int u, int p) {
    sz[u] = 1;
    for (int v : adj[u]) if (v != p) {
        DFS_size(v, u);
        sz[u] += sz[v];
    }
}

int cntFull = 0, ans = INT_MAX;

void update(int u, int p, int val) {
    int col = color[u];
    cnt[col] += val;
    if (cnt[col] == total[col] && val == 1) cntFull++;
    else if (cnt[col] == total[col] - 1 && val == -1) cntFull--;
    for (int v : adj[u]) if (v != p)
        update(v, u, val);
}

void DFS_calc(int u, int p) {
    int bigChild = 0;
    for (int v : adj[u]) if (v != p)
        if (bigChild == 0 || sz[bigChild] < sz[v])
            bigChild = v;

    for (int v : adj[u]) if (v != p && v != bigChild) {
        DFS_calc(v, u);
        update(v, u, -1);
    }

    if (bigChild) DFS_calc(bigChild, u);

    for (int v : adj[u]) if (v != p && v != bigChild)
        update(v, u, 1);

    cnt[color[u]]++;
    if (cnt[color[u]] == total[color[u]]) cntFull++;

    if (u != 1)
        minimize(ans, min(cntFull, nColor - cntFull));
}

void solve() {
    cin >> nNode >> nColor;
    FOR(i, 2, nNode) {
        int u, v;
        cin >> u >> v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    FOR(i, 1, nNode) cin >> color[i], total[color[i]]++;

    DFS_size(1, -1);
    DFS_calc(1, -1);

    cout << ans;
}

int32_t main() {
    if (fopen(task".inp", "r")) {
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    bool multitest = 0;
    int numTest = 1;
    if (multitest) cin >> numTest;

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

    return 0;
}

/* Lak lu theo dieu nhac!!!! */

Compilation message (stderr)

mergers.cpp: In function 'int32_t main()':
mergers.cpp:100:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  100 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
mergers.cpp:101:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  101 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 10
• Subtask 2: 0 / 24
• Subtask 3: 0 / 14
• Subtask 4: 0 / 22
• Subtask 5: 0 / 30