Submission #1341346

#	Time	Username	Problem	Language	Result	Execution time	Memory
1341346		doantaolaaidi	Mag (COCI16_mag)	C++20	0 / 120	269 ms	145488 KiB

mag

#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define AC "test"
#define foru(i, l, r) for (int i = (l); i <= (r); i++)
#define ford(i, l, r) for (int i = (l); i >= (r); i--)
#define fi first
#define se second

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vii;
typedef vector<ll> vll;

const ll inf = 1e9 + 7;
const ll linf = 1e18 + 7;
const int mod = 1e9 + 7;
const int maxn = 1e6 + 7;
const int base = 31;

void fastIO(){
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
}

ll mul(ll a, ll b){
    a%=mod;
    ll res = 0;
    while (b){
        if (b%2) res = (res + a)%mod;
        a = (a + a)%mod;
        b/=2;
    }
    return res;
}

ll Pow(ll a, ll b){
    ll ans = 1;
    while (b){
        if (b % 2) ans = mul(ans, a);
        a = mul(a, a);
        b/=2;
    }
    return ans;
}

ll n, u, v, val, res, a[maxn], dp[maxn], res1[maxn], res2[maxn];
vll g[maxn];

void dfs(int s, int pa = -1){
    if (a[s] == 1) dp[s] = 1;
    for (int tmp : g[s]){
        if (tmp == pa) continue;
        dfs(tmp, s);
        if (a[s] == 1){
            if (dp[tmp] > res1[s]){
                res2[s] = res1[s];
                res1[s] = dp[tmp];
            }
            else if (dp[tmp] > res2[s]) res2[s] = dp[tmp];
        }
    }
    if (a[s] == 1) res = max(res, res1[s] + res2[s] + 1);
}

void solve(){
    cin >> n;
    foru(i, 1, n - 1){
        cin >> u >> v;
        g[u].pb(v);
        g[v].pb(u);
    }
    val = linf;
    foru(i, 1, n){
        cin >> a[i];
        val = min(a[i], val);
    }
    if (val != 1){
        cout << val << "/1";
        return;
    }
    dfs(1);
    cout << "1/" << res;
}

int main(){
    fastIO();
    if (fopen(AC".inp", "r")){
        freopen(AC".inp", "r", stdin);
        freopen(AC".out", "w", stdout);
    }
    solve();
}

Compilation message (stderr)

mag.cpp: In function 'int main()':
mag.cpp:90:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   90 |         freopen(AC".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
mag.cpp:91:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   91 |         freopen(AC".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

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