Submission #643582

#	Time	Username	Problem	Language	Result	Execution time	Memory
643582		Vu_CG_Coder	Cat in a tree (BOI17_catinatree)	C++14	0 / 100	11 ms	19044 KiB

catinatree

/* [Author : Hoang Duy Vu] */
#include <bits/stdc++.h>
#define All(x) (x).begin(),(x).end()
#define ll long long
#define C make_pair
#define fi first
#define se second
#define two second.first
#define thr second.second
#define TASK "txt"
using namespace std;
template<typename T> bool maximize(T &res, const T &val) {
    if (res < val) { res = val; return true; } return false; }
template<typename T> bool minimize(T &res, const T &val) {
    if (res > val) { res = val; return true; } return false; }

typedef pair<int,int> ii;
typedef pair<int,ii> iii;
const int LOG = 20;
const int INF = 1e9 + 7;
const ll LNF = 1e18 + 7;
const int mod = 1e9 + 7;
const int N = 200100;

vector <int> a[N];
vector <int> dp[N][3];
int t[N] = {0};
int high[N] = {0};
int n , k;

void input()
{
    cin >> n >> k;
    for (int i = 1 ; i < n ; i++)
    {
        int x;
        cin >> x;
        a[x].push_back(i);
        a[i].push_back(x);
    }
}

void dfs(int u ,int par)
{
    int cnt = 0;
    dp[u][0].assign(1,0);

    for (int v : a[u])
    if (v != par)
    {
        dfs(v,u);
        int New = (cnt + 1)&1;
        
        maximize(high[u],high[v] + 1);
        dp[u][New].assign(high[u] + 10,0);

        for (int i = 0 ; i <= high[u] ; i++)
        {
            if (i < dp[u][cnt].size());
            dp[u][New][i] = dp[u][cnt][i];

            for (int j = max(i - 1,0) ; j <= high[v] ; j++)
            {
                int x = j + 1;

           //     if (u == 7) cout << u << " " << high[v] << " " << v << " " << i << " " << x << " " << k - x << " " << dp[v][t[v]][j] <<"\n";
                if (max(i,k - x) < dp[u][cnt].size())
                maximize(dp[u][New][i],dp[u][cnt][max(i,k - x)] + dp[v][t[v]][j]);
                else  maximize(dp[u][New][i],dp[v][t[v]][j]);
            }


        }
      //  if (u == 7) cout << v << " " << dp[u][New][1] << "\n";

        cnt = New;
    }

    t[u] = cnt;

    maximize(dp[u][t[u]][0],dp[u][t[u]][k] + 1);

    // cout << u << ":";

    // for (int i = 0 ; i <= high[u] ; i++) cout << dp[u][t[u]][i] << " ";
    // cout << "\n\n";
}

void solve()
{
    dfs(0,0);

    int res = 0;
    for (int i = 0 ; i <= high[0] ; i++) maximize(res,dp[0][t[0]][i]);

    cout << res;
}

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(NULL); cout.tie(NULL);
    if(fopen(TASK".inp", "r")){
    freopen(TASK".inp","r",stdin);
    freopen(TASK".out","w",stdout);
    }

    int tk;
    tk = 1;
   //cin >> tk;
    while (tk--)
    {
        input();
        solve();
    }
    return 0;
}

Compilation message (stderr)

catinatree.cpp: In function 'void dfs(int, int)':
catinatree.cpp:59:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   59 |             if (i < dp[u][cnt].size());
      |                 ~~^~~~~~~~~~~~~~~~~~~
catinatree.cpp:67:34: warning: comparison of integer expressions of different signedness: 'const int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   67 |                 if (max(i,k - x) < dp[u][cnt].size())
      |                     ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~
catinatree.cpp: In function 'int main()':
catinatree.cpp:104:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  104 |     freopen(TASK".inp","r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
catinatree.cpp:105:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  105 |     freopen(TASK".out","w",stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 11
• Subtask 2: 0 / 40
• Subtask 3: 0 / 49