oj.uz

Submission #943521

# Submission time Handle Problem Language Result Execution time Memory
943521 2024-03-11T14:50:45 Z Zero_OP Cat in a tree (BOI17_catinatree) C++14
100 / 100
 180 ms 54216 KB 
#include<bits/stdc++.h>

using namespace std;
using int64 = int64_t;

#define     REP(i, n) for(int i = 0, _n = n; i < _n; ++i)
#define    REPD(i, n) for(int i = n - 1; i >= 0; --i)
#define  FOR(i, l, r) for(int i = l, _r = r; i <= _r; ++i)
#define FORD(i, r, l) for(int i = r, _l = l; i >= _l; --i)
#define          left __left
#define         right __right
#define          prev __prev
#define          next __next
#define           div __div
#define            pb push_back
#define            pf push_front
#define         sz(v) (int)v.size()
#define      range(v) begin(v), end(v)
#define    compact(v) v.erase(unique(range(v)), end(v))
#define      debug(v) "[" #v " = " << (v) << "]"

template<typename T>
    bool minimize(T& a, const T& b){
        if(a > b){
            a = b;
            return true;
        }
        return false;
    }

template<typename T>
    bool maximize(T& a, const T& b){
        if(a < b){
            a = b;
            return true;
        }
        return false;
    }

template<int dimension, class T>
struct vec : public vector<vec<dimension - 1, T>> {
    static_assert(dimension > 0, "Dimension must be positive !\n");
    template<typename... Args>
    vec(int n = 0, Args... args) : vector<vec<dimension - 1, T>>(n, vec<dimension - 1, T>(args...)) {}
};

template<class T>
struct vec<1, T> : public vector<T> {
    vec(int n = 0, T val = T()) : vector<T>(n, val) {}
};

void init(void);
void process(void);

int main(){
    ios_base::sync_with_stdio(0); cin.tie(0);

    #define task "antuvu"
    if(fopen(task".inp", "r")){
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }

    int T = 1; //cin >> T;
    while(T--) {
        init();
        process();
    }

    return 0;
}

const int MAX = 2e5 + 5;

int n, d, timer_dfs, depth[MAX], spt[20][MAX * 2], pos[MAX], par[MAX], count_children[MAX], dp[MAX];
vector<int> adj[MAX];
bool del[MAX];

void init(){
    cin >> n >> d;
    FOR(i, 1, n - 1){
        int p; cin >> p;
        adj[p].pb(i);
        adj[i].pb(p);
    }
}

void pre_dfs(int u, int pre){
    spt[0][pos[u] = timer_dfs++] = u;
    for(int v : adj[u]) if(v != pre){
        depth[v] = depth[u] + 1;
        pre_dfs(v, u);
        spt[0][timer_dfs++] = u;
    }
}

int f(int a, int b){
    return depth[a] < depth[b] ? a : b;
}

void prepareRMQ(){
    for(int i = 1; (1 << i) <= timer_dfs; ++i){
        for(int j = 0; j + (1 << i) <= timer_dfs; ++j){
            spt[i][j] = f(spt[i - 1][j], spt[i - 1][j + (1 << (i - 1))]);
        }
    }
}

int getLCA(int u, int v){
    u = pos[u], v = pos[v];
    if(u > v) swap(u, v);
    int step = __lg(v - u + 1);
    return f(spt[step][u], spt[step][v - (1 << step) + 1]);
}

int get_distance(int u, int v){
    return depth[u] + depth[v] - 2 * depth[getLCA(u, v)];
}

int dfs_size(int u, int pre){
    count_children[u] = 1;
    for(int v : adj[u]) if(v != pre and !del[v]){
        count_children[u] += dfs_size(v, u);
    }
    return count_children[u];
}

int find_centroid(int u, int pre, int target){
    for(int v : adj[u]) if(v != pre and !del[v] and count_children[v] * 2 > target){
        return find_centroid(v, u, target);
    }
    return u;
}

void decompose(int u, int e){
    int c = find_centroid(u, e, dfs_size(u, e));
    del[c] = true; par[c] = e;

    for(int v : adj[c]) if(!del[v]) decompose(v, c);
}

void update(int u){
    int v = u;
    while(v != -1){
        minimize(dp[v], get_distance(v, u));
        v = par[v];
    }
}

int query(int u){
    int ans = INT_MAX, v = u;
    while(v != -1){
        minimize(ans, dp[v] + get_distance(u, v));
        v = par[v];
    }
    return ans;
}

void process(){
    pre_dfs(0, -1);
    prepareRMQ();
    decompose(0, -1);

    memset(dp, 0x3f, sizeof(dp));
    vector<pair<int, int>> nodes;
    REP(i, n){
        nodes.pb(make_pair(depth[i], i));
    }

    int ans = 0;
    sort(range(nodes), greater<pair<int, int>>());
    for(auto [x, u] : nodes){
        if(query(u) >= d){
            ++ans;
            update(u);
        }
    }
    cout << ans << '\n';
}

Compilation message

catinatree.cpp: In function 'void process()':
catinatree.cpp:172:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  172 |     for(auto [x, u] : nodes){
      |              ^
catinatree.cpp: In function 'int main()':
catinatree.cpp:60:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   60 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
catinatree.cpp:61:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   61 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 14684 KB Output is correct
2 Correct 2 ms 14684 KB Output is correct
3 Correct 3 ms 14684 KB Output is correct
4 Correct 3 ms 14680 KB Output is correct
5 Correct 3 ms 14680 KB Output is correct
6 Correct 3 ms 14684 KB Output is correct
7 Correct 3 ms 14684 KB Output is correct
8 Correct 2 ms 14680 KB Output is correct
9 Correct 4 ms 16732 KB Output is correct
10 Correct 3 ms 16868 KB Output is correct
11 Correct 3 ms 16824 KB Output is correct
12 Correct 3 ms 16732 KB Output is correct
13 Correct 2 ms 16732 KB Output is correct
14 Correct 3 ms 16732 KB Output is correct
15 Correct 3 ms 16732 KB Output is correct
16 Correct 3 ms 16732 KB Output is correct
17 Correct 3 ms 16732 KB Output is correct
18 Correct 3 ms 16732 KB Output is correct
19 Correct 3 ms 16868 KB Output is correct
20 Correct 3 ms 16728 KB Output is correct

Subtask #2
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 14684 KB Output is correct
2 Correct 2 ms 14684 KB Output is correct
3 Correct 3 ms 14684 KB Output is correct
4 Correct 3 ms 14680 KB Output is correct
5 Correct 3 ms 14680 KB Output is correct
6 Correct 3 ms 14684 KB Output is correct
7 Correct 3 ms 14684 KB Output is correct
8 Correct 2 ms 14680 KB Output is correct
9 Correct 4 ms 16732 KB Output is correct
10 Correct 3 ms 16868 KB Output is correct
11 Correct 3 ms 16824 KB Output is correct
12 Correct 3 ms 16732 KB Output is correct
13 Correct 2 ms 16732 KB Output is correct
14 Correct 3 ms 16732 KB Output is correct
15 Correct 3 ms 16732 KB Output is correct
16 Correct 3 ms 16732 KB Output is correct
17 Correct 3 ms 16732 KB Output is correct
18 Correct 3 ms 16732 KB Output is correct
19 Correct 3 ms 16868 KB Output is correct
20 Correct 3 ms 16728 KB Output is correct
21 Correct 4 ms 27228 KB Output is correct
22 Correct 3 ms 22876 KB Output is correct
23 Correct 4 ms 22876 KB Output is correct
24 Correct 3 ms 22876 KB Output is correct
25 Correct 4 ms 25176 KB Output is correct
26 Correct 4 ms 24924 KB Output is correct
27 Correct 4 ms 24924 KB Output is correct
28 Correct 4 ms 27228 KB Output is correct
29 Correct 4 ms 27228 KB Output is correct
30 Correct 5 ms 27228 KB Output is correct
31 Correct 4 ms 27228 KB Output is correct
32 Correct 4 ms 27224 KB Output is correct
33 Correct 5 ms 27228 KB Output is correct
34 Correct 5 ms 27228 KB Output is correct
35 Correct 5 ms 27224 KB Output is correct
36 Correct 4 ms 27228 KB Output is correct
37 Correct 4 ms 27196 KB Output is correct
38 Correct 5 ms 27228 KB Output is correct
39 Correct 4 ms 27224 KB Output is correct
40 Correct 5 ms 27228 KB Output is correct

Subtask #3
49.0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 14684 KB Output is correct
2 Correct 2 ms 14684 KB Output is correct
3 Correct 3 ms 14684 KB Output is correct
4 Correct 3 ms 14680 KB Output is correct
5 Correct 3 ms 14680 KB Output is correct
6 Correct 3 ms 14684 KB Output is correct
7 Correct 3 ms 14684 KB Output is correct
8 Correct 2 ms 14680 KB Output is correct
9 Correct 4 ms 16732 KB Output is correct
10 Correct 3 ms 16868 KB Output is correct
11 Correct 3 ms 16824 KB Output is correct
12 Correct 3 ms 16732 KB Output is correct
13 Correct 2 ms 16732 KB Output is correct
14 Correct 3 ms 16732 KB Output is correct
15 Correct 3 ms 16732 KB Output is correct
16 Correct 3 ms 16732 KB Output is correct
17 Correct 3 ms 16732 KB Output is correct
18 Correct 3 ms 16732 KB Output is correct
19 Correct 3 ms 16868 KB Output is correct
20 Correct 3 ms 16728 KB Output is correct
21 Correct 4 ms 27228 KB Output is correct
22 Correct 3 ms 22876 KB Output is correct
23 Correct 4 ms 22876 KB Output is correct
24 Correct 3 ms 22876 KB Output is correct
25 Correct 4 ms 25176 KB Output is correct
26 Correct 4 ms 24924 KB Output is correct
27 Correct 4 ms 24924 KB Output is correct
28 Correct 4 ms 27228 KB Output is correct
29 Correct 4 ms 27228 KB Output is correct
30 Correct 5 ms 27228 KB Output is correct
31 Correct 4 ms 27228 KB Output is correct
32 Correct 4 ms 27224 KB Output is correct
33 Correct 5 ms 27228 KB Output is correct
34 Correct 5 ms 27228 KB Output is correct
35 Correct 5 ms 27224 KB Output is correct
36 Correct 4 ms 27228 KB Output is correct
37 Correct 4 ms 27196 KB Output is correct
38 Correct 5 ms 27228 KB Output is correct
39 Correct 4 ms 27224 KB Output is correct
40 Correct 5 ms 27228 KB Output is correct
41 Correct 70 ms 46536 KB Output is correct
42 Correct 81 ms 40648 KB Output is correct
43 Correct 68 ms 41000 KB Output is correct
44 Correct 83 ms 40896 KB Output is correct
45 Correct 75 ms 40648 KB Output is correct
46 Correct 176 ms 48076 KB Output is correct
47 Correct 156 ms 48076 KB Output is correct
48 Correct 180 ms 48168 KB Output is correct
49 Correct 168 ms 48328 KB Output is correct
50 Correct 45 ms 40912 KB Output is correct
51 Correct 45 ms 40912 KB Output is correct
52 Correct 43 ms 41044 KB Output is correct
53 Correct 107 ms 48580 KB Output is correct
54 Correct 102 ms 48584 KB Output is correct
55 Correct 112 ms 48572 KB Output is correct
56 Correct 5 ms 27228 KB Output is correct
57 Correct 15 ms 35772 KB Output is correct
58 Correct 63 ms 46104 KB Output is correct
59 Correct 147 ms 54216 KB Output is correct
60 Correct 74 ms 47816 KB Output is correct
61 Correct 114 ms 47568 KB Output is correct