Submission #331470

#	Time	Username	Problem	Language	Result	Execution time	Memory
331470		BeanZ	Mag (COCI16_mag)	C++14	24 / 120	453 ms	157096 KiB

mag

// I_Love_LPL
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define endl '\n'
const int N = 1e6 + 5;
const int mod = 1e9 + 7;
const int lim = 100;
ll a[N];
vector<ll> node[N];
pair<ll, ll> dp[N];
bool cmp(ll x, ll y){
    return ((dp[x].first * dp[y].second) < (dp[x].second * dp[y].first));
}
pair<ll, ll> mul(pair<ll, ll> x, pair<ll, ll> y){
    return {x.first * y.first, x.second + y.second};
}
pair<ll, ll> cal(pair<ll, ll> x, pair<ll, ll> y){
    if ((x.first * y.second) <= (x.second * y.first)) return x;
    else return y;
}
pair<ll, ll> ans = {1e9, 1};
void dfs(ll u, ll p){
    dp[u] = {a[u], 1};
    for (auto j : node[u]){
        if (j == p) continue;
        dfs(j, u);
    }
    for (int i = 0; i < node[u].size(); i++){
        if (node[u][i] == p){
            swap(node[u][i], node[u][node[u].size() - 1]);
            node[u].pop_back();
            break;
        }
    }
    sort(node[u].begin(), node[u].end(), cmp);
    ans = cal(ans, dp[u]);
    if (node[u].size()){
        ll can1 = node[u][0];
        dp[u] = cal(mul(dp[u], dp[can1]), dp[u]);
        ans = cal(ans, dp[u]);
        if (node[u].size() >= 2){
            ll can2 = node[u][1];
            ans = cal(ans, mul(dp[u], dp[can2]));
        }
    }
}
int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    if (fopen("A.inp", "r")){
        freopen("test.inp", "r", stdin);
        freopen("test.out", "w", stdout);
    }
    ll n;
    cin >> n;
    for (int i = 1; i < n; i++){
        ll u, v;
        cin >> u >> v;
        node[u].push_back(v);
        node[v].push_back(u);
    }
    for (int i = 1; i <= n; i++) cin >> a[i];
    dfs(1, 1);
    ll gcd = __gcd(ans.first, ans.second);
    ans.first /= gcd;
    ans.second /= gcd;
    cout << ans.first << "/" << ans.second << endl;
}
/*
5
1 2
2 4
1 3
5 2
2
1
1
1
3
*/

Compilation message (stderr)

mag.cpp: In function 'void dfs(long long int, long long int)':
mag.cpp:29:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   29 |     for (int i = 0; i < node[u].size(); i++){
      |                     ~~^~~~~~~~~~~~~~~~
mag.cpp: In function 'int main()':
mag.cpp:52:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   52 |         freopen("test.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
mag.cpp:53:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   53 |         freopen("test.out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 12
• Subtask 2: 0 / 12
• Subtask 3: 0 / 12
• Subtask 4: 0 / 12
• Subtask 5: 12 / 12
• Subtask 6: 0 / 12
• Subtask 7: 12 / 12
• Subtask 8: 0 / 12
• Subtask 9: 0 / 12
• Subtask 10: 0 / 12