Submission #1091742

#	Time	Username	Problem	Language	Result	Execution time	Memory
1091742		Zero_OP	Min-max tree (BOI18_minmaxtree)	C++14	0 / 100	1068 ms	39248 KiB

minmaxtree

#include<bits/stdc++.h>

using namespace std;

#define sz(v) (int)v.size()
#define all(v) begin(v), end(v)
#define compact(v) v.erase(unique(all(v)), end(v))
#define dbg(v) "[" #v " = " << (v) << "]"
#define file(name) if(fopen(name".inp", "r")) {freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
#define rep(i, l, r) for(int i = (l); i < (r); ++i)

using ll = long long;
using vi = vector<int>;
using vl = vector<long long>;
using ld = long double;

template<typename T>
    bool minimize(T& a, const T& b){
        if(a > b){
            return a = b, true;
        }  return false;
    }

template<typename T>
    bool maximize(T& a, const T& b){
        if(a < b){
            return a = b, true;
        } return false;
    }

template<int dimension, typename T>
struct tensor : public vector<tensor<dimension - 1, T>> {
    static_assert(dimension > 0, "Dimension must be positive !\n");
    template<typename... Args>
    tensor(int n = 0, Args... args) : vector<tensor<dimension - 1, T>> (n, tensor<dimension - 1, T>(args...)) {}
};

template<typename T>
struct tensor<1, T> : public vector<T> {
    tensor(int n = 0, T val = T()) : vector<T>(n, val) {}
};

const int INF = 1e7 + 5;

struct MaximumBipartiteMatching {
    int n;
    vector< vector<int> > ke;
    vector< bool > seen;
    vector< int > matchL, matchR;

    MaximumBipartiteMatching(int n) : n(n), ke(n), seen(n, false), matchL(n, -1), matchR(n, -1) {}

    void addEdge(int u, int v) {
        ke[u].push_back(v);
    }

    bool bpm(int u) {
        for(__typeof(ke[u].begin()) v = ke[u].begin(); v != ke[u].end(); ++v) {
            if (seen[*v]) continue;
            seen[*v] = true;

            if (matchR[*v] < 0 || bpm(matchR[*v])) {
                matchL[u] = *v;
                matchR[*v] = u;
                return true;
            }
        }
        return false;
    }

    int match() {
        int res = 0;
        for(int i = 0; i < n; ++i) {
            for(int i = 0; i < n; ++i) seen[i] = false;
            if (bpm(i)) ++res;
        }
        return res;
    }
};

const int MAX = 7e4 + 5;
const int inf = 1e9 + 7;

int n, q, head[MAX], depth[MAX], sz[MAX], heavy[MAX], par[MAX], pos[MAX], timerHLD;
vector<int> adj[MAX];
vector<pair<int, int>> addEdge[2][MAX], deleteEdge[2][MAX];
int minEdge[MAX], maxEdge[MAX];

void dfs(int u){
    sz[u] = 1;
    for(int v : adj[u]){
        adj[v].erase(find(all(adj[v]), u));
        depth[v] = depth[u] + 1;
        par[v] = u;

        dfs(v);
        sz[u] += sz[v];
        if(sz[heavy[u]] < sz[v]){
            heavy[u] = v;
        }
    }
}

void dfsHLD(int u, int chain){
    head[u] = chain;

    if(heavy[u]){
        dfsHLD(heavy[u], chain);
        for(int v : adj[u]){
            if(v != heavy[u]){
                dfsHLD(v, v);
            }
        }
    }
}

int getLCA(int u, int v){
    while(head[u] != head[v]){
        if(depth[head[u]] < depth[head[v]]) swap(u, v);
        u = par[head[u]];
    }
    return (depth[u] < depth[v] ? u : v);
}

int queries[MAX];
multiset<pair<int, int>> st[2][MAX];

void dfs_solve(int u){
    for(int v : adj[u]){
        dfs_solve(v);
        for(int i = 0; i < 2; ++i){
            if(sz(st[i][u]) < sz(st[i][v])){
                swap(st[i][u], st[i][v]);
            }

            for(auto it : st[i][v]) st[i][u].insert(it);
        }
    }

    for(int i = 0; i < 2; ++i){
        for(auto it : addEdge[i][u]) st[i][u].insert(it);
        for(auto it : deleteEdge[i][u]){
            st[i][u].erase(st[i][u].lower_bound(it));
            st[i][u].erase(st[i][u].lower_bound(it));
        }
    }

    minEdge[u] = (st[0][u].empty() ? -1 : st[0][u].begin() -> second);
    maxEdge[u] = (st[1][u].empty() ? -1 : st[1][u].rbegin() -> second);
}

void testcase(){
    cin >> n;
    for(int i = 1; i < n; ++i){
        int u, v;
        cin >> u >> v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }

    dfs(1);
    dfsHLD(1, 1);

    cin >> q;
    for(int i = 1; i <= q; ++i){
        char op; int u, v, w;
        cin >> op >> u >> v >> w;

        int type = (op == 'm' ? 0 : 1);
        int lca = getLCA(u, v);

        addEdge[type][u].push_back({w, i});
        addEdge[type][v].push_back({w, i});
        deleteEdge[type][lca].push_back({w, i}); //remember x2 times

        queries[i] = w;
    }

    dfs_solve(1);

    MaximumBipartiteMatching Match(n + q + 1);
    for(int i = 2; i <= n; ++i){
        if(minEdge[i] != -1){
            Match.addEdge(i, n + minEdge[i]);
        }

        if(maxEdge[i] != -1){
            Match.addEdge(i, n + maxEdge[i]);
        }
    }

    int ret = Match.match();
    vector<int> resEdge(n + 1);
    for(int i = 2; i <= n; ++i){
        if(Match.matchL[i] >= 0){
            resEdge[i] = queries[Match.matchL[i] - n];
        } else{
            resEdge[i] = inf;
        }
    }

    for(int i = 2; i <= n; ++i){
        cout << par[i] << ' ' << i << ' ' << resEdge[i] << '\n';
    }
}

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

    file("task");

    int T = 1;
    // cin >> T;
    while(T--){
        testcase();
    }

    return 0;
}

Compilation message (stderr)

minmaxtree.cpp: In function 'void testcase()':
minmaxtree.cpp:192:9: warning: unused variable 'ret' [-Wunused-variable]
  192 |     int ret = Match.match();
      |         ^~~
minmaxtree.cpp: In function 'int main()':
minmaxtree.cpp:9:55: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    9 | #define file(name) if(fopen(name".inp", "r")) {freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
      |                                                ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
minmaxtree.cpp:211:5: note: in expansion of macro 'file'
  211 |     file("task");
      |     ^~~~
minmaxtree.cpp:9:88: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    9 | #define file(name) if(fopen(name".inp", "r")) {freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
      |                                                                                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
minmaxtree.cpp:211:5: note: in expansion of macro 'file'
  211 |     file("task");
      |     ^~~~

• Subtask 1: 0 / 7
• Subtask 2: 0 / 22
• Subtask 3: 0 / 29
• Subtask 4: 0 / 42