Submission #1080958

#	Time	Username	Problem	Language	Result	Execution time	Memory
1080958		cpptowin	Cat in a tree (BOI17_catinatree)	C++17	100 / 100	48 ms	40020 KiB

catinatree

#include <bits/stdc++.h>
#define fo(i, d, c) for (int i = d; i <= c; i++)
#define fod(i, c, d) for (int i = c; i >= d; i--)
#define maxn 1000010
#define N 1010
#define fi first
#define se second
#define pb emplace_back
#define en cout << "\n";
#define int long long
#define inf (int)1e18
#define bitcount(x) __builtin_popcountll(x)
#define pii pair<int, int>
#define vii vector<pii>
#define lb(x) x & -x
#define bit(i, j) ((i >> j) & 1)
#define offbit(i, j) (i ^ (1LL << j))
#define onbit(i, j) (i | (1LL << j))
#define vi vector<int>
#define all(x) x.begin(), x.end()
#define ss(x) (int)x.size()
template <typename T1, typename T2>
bool minimize(T1 &a, T2 b)
{
    if (a > b)
    {
        a = b;
        return true;
    }
    return false;
}
template <typename T1, typename T2>
bool maximize(T1 &a, T2 b)
{
    if (a < b)
    {
        a = b;
        return true;
    }
    return false;
}
using namespace std;
const int nsqrt = 450;
const int mod = 1e9 + 7;
void add(int &x, int k)
{
    x += k;
    x %= mod;
    if(x < 0) x += mod;
}
void del(int &x, int k)
{
    x -= k;
    x %= mod;
    if(x < 0) x += mod;
}
vi ke[maxn];
pii dp[maxn];
int n,d;
void dfs(int u,int par = 0) 
{
    dp[u] = {1,0};
    for(int v : ke[u]) if(v != par) 
    {
        dfs(v,u);
        dp[u].fi += dp[v].fi;
        if(dp[u].se + dp[v].se + 1 < d)
        {
            dp[u].fi--;
            maximize(dp[u].se,dp[v].se + 1);
        }
        else minimize(dp[u].se,dp[v].se + 1);
    }
}
main()
{
#define name "TASK"
    if (fopen(name ".inp", "r"))
    {
        freopen(name ".inp", "r", stdin);
        freopen(name ".out", "w", stdout);
    }
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cin >> n >> d;
    fo(i,2,n)
    {
        int x;
        cin >> x;
        ke[x + 1].pb(i);
    }
    dfs(1);
    cout << dp[1].fi;
}

Compilation message (stderr)

catinatree.cpp:75:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   75 | main()
      | ^~~~
catinatree.cpp: In function 'int main()':
catinatree.cpp:80:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   80 |         freopen(name ".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
catinatree.cpp:81:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   81 |         freopen(name ".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 40 / 40
• Subtask 3: 49 / 49