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답안 #143533

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
143533 2019-08-14T14:07:10 Z popovicirobert Mousetrap (CEOI17_mousetrap) C++14
100 / 100
 1072 ms 161780 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], lvl[MAXN + 1];

void dfs(int nod, int par) {
    father[nod] = par;
    lvl[nod] = lvl[par] + 1;
    for(auto it : g[nod]) {
        if(it != par) {
            dfs(it, nod);
        }
    }
}

int dp[MAXN + 1];
bool vis[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;
    }
}

void go(int nod, int par, int sum) {
    int sz = (int) g[nod].size() - 1;
    pair <int, int> mx = {0, 0};
    for(auto it : g[nod]) {
        if(it != par) {
            go(it, nod, sum + sz - vis[nod]);
            combine(mx, dp[it]);
        }
    }
    if(sz > 1) {
        dp[nod] = mx.second;
    }
    else {
         dp[nod] = sz - vis[nod] + sum;
    }
}

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);
    }

    dfs(t, 0);

    int nod = m, dst = 1;
    vector < pair <int, int> > nodes; //nodes.push_back({m, 0});
    for(auto it : g[m]) {
        if(it != father[m])
            nodes.push_back({it, 1});
    }

    while(father[nod] != t) {
        dst++;
        for(auto it : g[father[nod]]) {
            if(it != nod && lvl[it] == lvl[nod]) {
                nodes.push_back({it, dst});
            }
        }
        nod = father[nod];
        vis[nod] = 1;
    }
    go(nod, t, 0);

    auto check = [&](int X) -> bool {
        int cnt = 0, num = 0;
        for(i = 0; i < nodes.size(); i++) {
            int last = (i == 0 ? -1 : nodes[i - 1].second);
            if(last != nodes[i].second) {
                num = 0;
            }
            if(dp[nodes[i].first] + cnt - num > X) {
                cnt++, num++;
            }
            if(cnt > nodes[i].second) {
                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:154:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(i = 0; i < nodes.size(); i++) {
                    ~~^~~~~~~~~~~~~~

Subtask #1
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 23 ms 23928 KB Output is correct
2 Correct 23 ms 23808 KB Output is correct
3 Correct 24 ms 23800 KB Output is correct
4 Correct 23 ms 23800 KB Output is correct
5 Correct 24 ms 23932 KB Output is correct
6 Correct 23 ms 23772 KB Output is correct
7 Correct 23 ms 23800 KB Output is correct
8 Correct 24 ms 23800 KB Output is correct
9 Correct 23 ms 23928 KB Output is correct
10 Correct 24 ms 23900 KB Output is correct

Subtask #2
25.0 / 25.0

# 결과 실행 시간 메모리 Grader output
1 Correct 442 ms 66996 KB Output is correct
2 Correct 389 ms 62580 KB Output is correct
3 Correct 1056 ms 68228 KB Output is correct
4 Correct 505 ms 45992 KB Output is correct
5 Correct 1056 ms 68144 KB Output is correct
6 Correct 1047 ms 68144 KB Output is correct

Subtask #3
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 23 ms 23928 KB Output is correct
2 Correct 23 ms 23808 KB Output is correct
3 Correct 24 ms 23800 KB Output is correct
4 Correct 23 ms 23800 KB Output is correct
5 Correct 24 ms 23932 KB Output is correct
6 Correct 23 ms 23772 KB Output is correct
7 Correct 23 ms 23800 KB Output is correct
8 Correct 24 ms 23800 KB Output is correct
9 Correct 23 ms 23928 KB Output is correct
10 Correct 24 ms 23900 KB Output is correct
11 Correct 24 ms 23800 KB Output is correct
12 Correct 24 ms 23928 KB Output is correct
13 Correct 23 ms 23928 KB Output is correct
14 Correct 24 ms 24056 KB Output is correct
15 Correct 24 ms 23928 KB Output is correct
16 Correct 23 ms 23932 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 24056 KB Output is correct
20 Correct 23 ms 23928 KB Output is correct
21 Correct 23 ms 23932 KB Output is correct
22 Correct 24 ms 23900 KB Output is correct

Subtask #4
35.0 / 35.0

# 결과 실행 시간 메모리 Grader output
1 Correct 23 ms 23928 KB Output is correct
2 Correct 23 ms 23808 KB Output is correct
3 Correct 24 ms 23800 KB Output is correct
4 Correct 23 ms 23800 KB Output is correct
5 Correct 24 ms 23932 KB Output is correct
6 Correct 23 ms 23772 KB Output is correct
7 Correct 23 ms 23800 KB Output is correct
8 Correct 24 ms 23800 KB Output is correct
9 Correct 23 ms 23928 KB Output is correct
10 Correct 24 ms 23900 KB Output is correct
11 Correct 442 ms 66996 KB Output is correct
12 Correct 389 ms 62580 KB Output is correct
13 Correct 1056 ms 68228 KB Output is correct
14 Correct 505 ms 45992 KB Output is correct
15 Correct 1056 ms 68144 KB Output is correct
16 Correct 1047 ms 68144 KB Output is correct
17 Correct 24 ms 23800 KB Output is correct
18 Correct 24 ms 23928 KB Output is correct
19 Correct 23 ms 23928 KB Output is correct
20 Correct 24 ms 24056 KB Output is correct
21 Correct 24 ms 23928 KB Output is correct
22 Correct 23 ms 23932 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 24056 KB Output is correct
26 Correct 23 ms 23928 KB Output is correct
27 Correct 23 ms 23932 KB Output is correct
28 Correct 24 ms 23900 KB Output is correct
29 Correct 23 ms 23800 KB Output is correct
30 Correct 438 ms 67100 KB Output is correct
31 Correct 438 ms 67140 KB Output is correct
32 Correct 519 ms 161780 KB Output is correct
33 Correct 507 ms 160872 KB Output is correct
34 Correct 1050 ms 68216 KB Output is correct
35 Correct 1072 ms 68080 KB Output is correct
36 Correct 1031 ms 79280 KB Output is correct
37 Correct 1029 ms 79400 KB Output is correct
38 Correct 870 ms 81000 KB Output is correct
39 Correct 838 ms 81160 KB Output is correct
40 Correct 846 ms 81116 KB Output is correct