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답안 #143531

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
143531 2019-08-14T13:59:58 Z popovicirobert Mousetrap (CEOI17_mousetrap) C++14
100 / 100
 1006 ms 178596 KB 
#include <bits/stdc++.h>
#define lsb(x) (x & (-x))
#define ll long long
#define ull unsigned long long



/*const int MOD = ;

inline int lgput(int a, int b) {
    int ans = 1;
    while(b > 0) {
        if(b & 1) ans = (1LL * ans * a) % MOD;
        b >>= 1;
        a = (1LL * a * a) % MOD;
    }
    return ans;
}

inline void mod(int &x) {
    if(x >= MOD)
        x -= MOD;
}

inline void add(int &x, int y) {
    x += y;
    mod(x);
}

inline void sub(int &x, int y) {
    x += MOD - y;
    mod(x);
}

inline void mul(int &x, int y) {
    x = (1LL * x * y) % MOD;
}

inline int inv(int x) {
    return lgput(x, MOD - 2);
}*/

/*int fact[], invfact[];

inline void prec(int n) {
    fact[0] = 1;
    for(int i = 1; i <= n; i++) {
        fact[i] = (1LL * fact[i - 1] * i) % MOD;
    }
    invfact[n] = lgput(fact[n], MOD - 2);
    for(int i = n - 1; i >= 0; i--) {
        invfact[i] = (1LL * invfact[i + 1] * (i + 1)) % MOD;
    }
}

inline int comb(int n, int k) {
    if(n < k) return 0;
    return (1LL * fact[n] * (1LL * invfact[k] * invfact[n - k] % MOD)) % MOD;
}*/

using namespace std;

const int MAXN = (int) 1e6;

vector <int> g[MAXN + 1];
int father[MAXN + 1];

inline void combine(pair <int, int> &mx, int cur) {
    if(mx.first < cur) {
        mx.second = mx.first;
        mx.first = cur;
    }
    else if(mx.second < cur) {
        mx.second = cur;
    }
}

int dp[MAXN + 1];

void go(int nod, int par) {
    father[nod] = par;
    if(par != 0) {
        g[nod].erase(find(g[nod].begin(), g[nod].end(), par));
    }
    pair <int, int> mx = {0, 0};
    for(auto it : g[nod]) {
        go(it, nod);
        combine(mx, dp[it]);
    }
    dp[nod] = mx.second + g[nod].size();
}

int main() {
#if 0
    ifstream cin("A.in");
    ofstream cout("A.out");
#endif
    int i, n, t, m;
    ios::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);

    cin >> n >> t >> m;

    if(m == t) {
        cout << 0;
        return 0;
    }

    for(i = 1; i < n; i++) {
        int x, y;
        cin >> x >> y;
        g[x].push_back(y);
        g[y].push_back(x);
    }

    go(t, 0);

    vector <int> anc, sp;
    int nod = m;
    while(nod != t) {
        anc.push_back(nod);
        sp.push_back(0);
        nod = father[nod];
    }

    sp.push_back(0);
    for(i = (int) sp.size() - 2; i >= 0; i--) {
        sp[i] = sp[i + 1] + (int) g[anc[i]].size() - (i > 0);
    }

    auto check = [&](int X) -> bool {
        int cnt = 0;
        for(i = 0; i < anc.size(); i++) {
            int last = (i == 0 ? 0 : anc[i - 1]), num = 0;
            for(auto it : g[anc[i]]) {
                if(last == it) continue;

                if(cnt + dp[it] + sp[i] - num > X) {
                    cnt++, num++;
                }
                if(cnt > i + 1) {
                    return 0;
                }
            }
        }
        return cnt <= X;
    };

    int res = -1;
    for(int step = 1 << 20; step; step >>= 1) {
        if(check(res + step) == 0) {
            res += step;
        }
    }

    cout << res + 1;

    return 0;
}

Compilation message

mousetrap.cpp: In lambda function:
mousetrap.cpp:133:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(i = 0; i < anc.size(); i++) {
                    ~~^~~~~~~~~~~~

Subtask #1
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 29 ms 23804 KB Output is correct
2 Correct 24 ms 23800 KB Output is correct
3 Correct 24 ms 23800 KB Output is correct
4 Correct 24 ms 23800 KB Output is correct
5 Correct 24 ms 23804 KB Output is correct
6 Correct 24 ms 23800 KB Output is correct
7 Correct 28 ms 23804 KB Output is correct
8 Correct 26 ms 23928 KB Output is correct
9 Correct 24 ms 23804 KB Output is correct
10 Correct 24 ms 23800 KB Output is correct

Subtask #2
25.0 / 25.0

# 결과 실행 시간 메모리 Grader output
1 Correct 424 ms 63000 KB Output is correct
2 Correct 377 ms 59000 KB Output is correct
3 Correct 898 ms 64268 KB Output is correct
4 Correct 430 ms 43988 KB Output is correct
5 Correct 903 ms 64108 KB Output is correct
6 Correct 988 ms 64092 KB Output is correct

Subtask #3
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 29 ms 23804 KB Output is correct
2 Correct 24 ms 23800 KB Output is correct
3 Correct 24 ms 23800 KB Output is correct
4 Correct 24 ms 23800 KB Output is correct
5 Correct 24 ms 23804 KB Output is correct
6 Correct 24 ms 23800 KB Output is correct
7 Correct 28 ms 23804 KB Output is correct
8 Correct 26 ms 23928 KB Output is correct
9 Correct 24 ms 23804 KB Output is correct
10 Correct 24 ms 23800 KB Output is correct
11 Correct 23 ms 23800 KB Output is correct
12 Correct 25 ms 23836 KB Output is correct
13 Correct 25 ms 23932 KB Output is correct
14 Correct 24 ms 23928 KB Output is correct
15 Correct 29 ms 23900 KB Output is correct
16 Correct 28 ms 23928 KB Output is correct
17 Correct 23 ms 23928 KB Output is correct
18 Correct 24 ms 23928 KB Output is correct
19 Correct 24 ms 23928 KB Output is correct
20 Correct 24 ms 23928 KB Output is correct
21 Correct 24 ms 23928 KB Output is correct
22 Correct 24 ms 23800 KB Output is correct

Subtask #4
35.0 / 35.0

# 결과 실행 시간 메모리 Grader output
1 Correct 29 ms 23804 KB Output is correct
2 Correct 24 ms 23800 KB Output is correct
3 Correct 24 ms 23800 KB Output is correct
4 Correct 24 ms 23800 KB Output is correct
5 Correct 24 ms 23804 KB Output is correct
6 Correct 24 ms 23800 KB Output is correct
7 Correct 28 ms 23804 KB Output is correct
8 Correct 26 ms 23928 KB Output is correct
9 Correct 24 ms 23804 KB Output is correct
10 Correct 24 ms 23800 KB Output is correct
11 Correct 424 ms 63000 KB Output is correct
12 Correct 377 ms 59000 KB Output is correct
13 Correct 898 ms 64268 KB Output is correct
14 Correct 430 ms 43988 KB Output is correct
15 Correct 903 ms 64108 KB Output is correct
16 Correct 988 ms 64092 KB Output is correct
17 Correct 23 ms 23800 KB Output is correct
18 Correct 25 ms 23836 KB Output is correct
19 Correct 25 ms 23932 KB Output is correct
20 Correct 24 ms 23928 KB Output is correct
21 Correct 29 ms 23900 KB Output is correct
22 Correct 28 ms 23928 KB Output is correct
23 Correct 23 ms 23928 KB Output is correct
24 Correct 24 ms 23928 KB Output is correct
25 Correct 24 ms 23928 KB Output is correct
26 Correct 24 ms 23928 KB Output is correct
27 Correct 24 ms 23928 KB Output is correct
28 Correct 24 ms 23800 KB Output is correct
29 Correct 24 ms 23800 KB Output is correct
30 Correct 438 ms 76316 KB Output is correct
31 Correct 426 ms 76432 KB Output is correct
32 Correct 644 ms 178596 KB Output is correct
33 Correct 521 ms 170276 KB Output is correct
34 Correct 907 ms 77376 KB Output is correct
35 Correct 912 ms 77440 KB Output is correct
36 Correct 1006 ms 87688 KB Output is correct
37 Correct 948 ms 87652 KB Output is correct
38 Correct 859 ms 90636 KB Output is correct
39 Correct 794 ms 90572 KB Output is correct
40 Correct 823 ms 90632 KB Output is correct