Submission #797369

#	Time	Username	Problem	Language	Result	Execution time	Memory
797369		Sam_a17	Min-max tree (BOI18_minmaxtree)	C++17	0 / 100	191 ms	36376 KiB

minmaxtree

#define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
// #include <atcoder/all>
#include <cstdio>
using namespace std;
 
#ifndef ONLINE_JUDGE
#define dbg(x) cerr << #x <<" "; print(x); cerr << endl;
#else
#define dbg(x)
#endif
 
#define sz(x) (int((x).size()))
#define len(x) (int)x.length()
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define clr(x) (x).clear()
#define blt(x) __builtin_popcount(x)
#define uniq(x) x.resize(unique(all(x)) - x.begin());
 
#define pb push_back
#define popf pop_front
#define popb pop_back
#define ld long double
#define ll long long
 
void print(long long t) {cerr << t;}
void print(int t) {cerr << t;}
void print(string t) {cerr << t;}
void print(char t) {cerr << t;}
void print(double t) {cerr << t;}
void print(unsigned long long t) {cerr << t;}
void print(long double t) {cerr << t;}
 
template <class T, class V> void print(pair <T, V> p);
template <class T> void print(vector <T> v);
template <class T> void print(set <T> v);
template <class T, class V> void print(map <T, V> v);
template <class T> void print(multiset <T> v);
template <class T> void print(T v[],T n) {cerr << "["; for(int i = 0; i < n; i++) {cerr << v[i] << " ";} cerr << "]";}
template <class T, class V> void print(pair <T, V> p) {cerr << "{"; print(p.first); cerr << ","; print(p.second); cerr << "}";}
template <class T> void print(vector <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(deque <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(set <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(multiset <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T, class V> void print(map <T, V> v) {cerr << "[ "; for (auto i : v) {print(i); cerr << " ";} cerr << "]";}
 
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
#define nl '\n'
 
// for random generations
mt19937 myrand(chrono::steady_clock::now().time_since_epoch().count());
// mt19937 myrand(131);
 
// for grid problems
int dx[8] = {1,0,-1,0,1,-1,1,-1};
int dy[8] = {0,1,0,-1,1,1,-1,-1};
char ch[4] = {'v', '>', '^', '<'};
 
long long ka() {
    long long x = 0;
    bool z = false;
    while (1)
    {
        char y = getchar();
        if (y == '-')
            z = true;
        else if ('0' <= y && y <= '9')
            x = x * 10 + y - '0';
        else
        {
            if (z)
                x *= -1;
            return x;
        }
    }
}
 
// lowest / (1 << 17) >= 1e5 / (1 << 18) >= 2e5 / (1 << 21) >= 1e6
void fastIO() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr); cout.tie(nullptr);
}
// file in/out
void setIO(string str = "") {
  fastIO();
 
  if (str != "") {
    freopen((str + ".in").c_str(), "r", stdin);
    freopen((str + ".out").c_str(), "w", stdout);
  } else if(str == "input") {
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
  }
}
 
// Indexed Set
template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

const int N = 1e5 + 10, LOG = 23, inf = 1e9;
vector<int> adj[N], to_add[N], to_del[N];
int depths[N], up[N][LOG];
multiset<int> mt[N];
int n;

void dfsr(int node, int parent, int depth) {
  for(auto i: adj[node]) {
    if(i == parent) continue;
    up[i][0] = node;
    for(int j = 1; j < LOG; j++) {
      up[i][j] = up[up[i][j - 1]][j - 1];
    } depths[i] = depths[node] + 1;
    dfsr(i, node, depth + 1);
  }
}

int lca(int a, int b) {
  if(a == b) {
    return a;
  }

  if(depths[a] > depths[b]) {
    swap(a, b);
  }

  int delta = depths[b] - depths[a];
  for(int i = 0; i < LOG; i++) {
    if(delta & (1 << i)) {
      b = up[b][i];
    }
  }

  if(a == b) {
    return a;
  }

  for(int i = LOG - 1; i >= 0; i--) {
    if(up[a][i] != up[b][i]) {
      a = up[a][i], b = up[b][i];
    }
  }
  return up[a][0];
}

struct edges {
  int a, b;
  int cost;
};
vector<edges> ans;

void dfs(int node, int parent) {
  for(auto i: adj[node]) {
    if(i == parent) continue;
    dfs(i, node);

    if(sz(mt[i]) > sz(mt[node])) {
      mt[node].swap(mt[i]);
    }

    for(auto i: mt[i]) {
      mt[node].insert(i);
    }
    mt[i].clear();
  }

  for(auto i: to_add[node]) {
    mt[node].insert(i);
  }

  for(auto i: to_del[node]) {
    mt[node].erase(mt[node].find(i));
  }

  if(parent) {
    if(!mt[node].empty()) {
      ans.push_back({parent, node, *mt[node].begin()});
    } else {
      ans.push_back({parent, node, inf});
    }
  }
}

void solve_() {
  cin >> n;

  for(int i = 1; i <= n - 1; i++) {
    int a, b; cin >> a >> b;
    adj[a].push_back(b);
    adj[b].push_back(a);
  }
  
  dfsr(1, 0, 0);

  int q; cin >> q;
  for(int i = 1; i <= q; i++) {
    char ch; cin >> ch;
    int a, b; cin >> a >> b;
    int cost; cin >> cost;
    
    assert(a != b);
    if(ch == 'M') {
      int lc = lca(a, b);
      to_add[a].push_back(cost);
      to_add[b].push_back(cost);
      to_del[lc].push_back(cost);
    } 
  }

  dfs(1, 0);

  assert(sz(ans) == n - 1);
  for(auto i: ans) {
    cout << i.a << " " << i.b << " " << i.cost << '\n';
  }
}
 
int main() {
  setIO();
 
  auto solve = [&](int test_case)-> void {
    while(test_case--) {
      solve_();
    }
  };
 
  int test_cases = 1;
  // cin >> test_cases;
  solve(test_cases);
 
  return 0;
} 

Compilation message (stderr)

minmaxtree.cpp: In function 'void setIO(std::string)':
minmaxtree.cpp:90:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   90 |     freopen((str + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
minmaxtree.cpp:91:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   91 |     freopen((str + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
minmaxtree.cpp:93:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   93 |     freopen("input.txt", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
minmaxtree.cpp:94:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   94 |     freopen("output.txt", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

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