oj.uz

Submission #78906

# Submission time Handle Problem Language Result Execution time Memory
78906 2018-10-09T14:29:24 Z bogdan10bos Min-max tree (BOI18_minmaxtree) C++14
100 / 100
 218 ms 89396 KB 
#include <bits/stdc++.h>

using namespace std;

//#define FILE_IO

typedef pair<int, int> pii;
typedef pair<pii, int> p3i;

const int NMAX = 70005;

p3i chn[NMAX];
int N, E, K;
int h[NMAX], f[NMAX], eul[NMAX], lg2[2 * NMAX], rmq[18][2 * NMAX];
int st[NMAX], dr[NMAX], c[NMAX], up[NMAX];
vector<int> chnmn, chnmx, edg[NMAX];

void DFS(int nod, int fth)
{
    f[nod] = fth;
    h[nod] = h[fth] + 1;
    rmq[0][++E] = nod;
    eul[nod] = E;
    for(auto nxt: edg[nod])
        if(nxt != fth)
        {
            DFS(nxt, nod);
            rmq[0][++E] = nod;
        }
}

int minh(int a, int b) { return (h[a] < h[b] ? a : b); }
int LCA(int a, int b)
{
    int pa = eul[a], pb = eul[b];
    if(pa > pb) swap(pa, pb);
    int lg = lg2[pb - pa + 1];
    return minh(rmq[lg][pa], rmq[lg][pb - (1 << lg) + 1]);
}

int Up(int x) { if(up[x] == x) return x; return up[x] = Up(up[x]); }

void color(int x, int y, int val)
{
    x = Up(x); y = Up(y);
    while(x != y)
    {
        c[x] = val;
        up[x] = Up(f[x]);
        x = Up(x);
    }
}

namespace Matching
{
    int N, F;
    int node[2 * NMAX];
    int mtc[2 * NMAX], f[2 * NMAX];
    vector<int> edg[2 * NMAX];

    void setN(int _N) { N = _N; }

    void addEdge(int x, int y)
    {
        edg[x].push_back(y);
        edg[y].push_back(x);
    }

    int match(int x)
    {
        if(f[x] == F)   return 0;
        f[x] = F;

        for(auto nxt: edg[x])
            if(!mtc[nxt])
            {
                mtc[nxt] = x;
                mtc[x] = nxt;
                return 1;
            }
        for(auto nxt: edg[x])
            if( match(mtc[nxt]) )
            {
                mtc[nxt] = x;
                mtc[x] = nxt;
                return 1;
            }

        return 0;
    }

    void randomize()
    {
        mt19937 gen(chrono::high_resolution_clock::now().time_since_epoch().count());
        for(int i = 1; i <= N; i++)
            shuffle(edg[i].begin(), edg[i].end(), gen);
        for(int i = 1; i <= N; i++) node[i] = i;
        shuffle(node + 1, node + N + 1, gen);
    }

    void solve()
    {
        randomize();
        bool newm = true;
        F = 0;
        while(newm)
        {
            F++;
            newm = false;
            for(int i = 1; i <= N; i++)
                if(!mtc[ node[i] ])
                    if( match(node[i]) )
                        newm = true;
        }
    }
}

int main()
{
    #ifdef FILE_IO
    freopen("1.in", "r", stdin);
    freopen("1.out", "w", stdout);
    #endif

    scanf("%d", &N);
    for(int i = 1; i < N; i++)
    {
        int x, y;
        scanf("%d%d", &x, &y);
        edg[x].push_back(y);
        edg[y].push_back(x);
    }

    DFS(1, 0);
    for(int i = 2; i <= E; i++) lg2[i] = 1 + lg2[i >> 1];
    for(int i = 1; (1 << i) <= E; i++)
        for(int j = 1; j + (1 << i) - 1 <= E; j++)
            rmq[i][j] = minh(rmq[i - 1][j], rmq[i - 1][j + (1 << (i - 1))]);

    scanf("%d\n", &K);
    for(int i = 1; i <= K; i++)
    {
        char ch;
        int x, y, val;
        scanf("%c %d%d%d\n", &ch, &x, &y, &val);
        chn[i] = { {x, y}, val };
        if(ch == 'm')   chnmn.push_back(i);
        else if(ch == 'M')  chnmx.push_back(i);
    }

    sort(chnmn.begin(), chnmn.end(),
         [](int a, int b) { return chn[a].second > chn[b].second; });
    sort(chnmx.begin(), chnmx.end(),
         [](int a, int b) { return chn[a].second < chn[b].second; });

    Matching::setN(N + K);

    for(int i = 1; i <= N; i++) up[i] = i, c[i] = 0;
    for(auto id: chnmn)
    {
        int x = chn[id].first.first, y = chn[id].first.second;
        int val = chn[id].second;
        int lca = LCA(x, y);
        color(x, lca, id);
        color(y, lca, id);
    }
    for(int i = 1; i <= N; i++)
        if(c[i] != 0)
            Matching::addEdge(i, c[i] + N);

    for(int i = 1; i <= N; i++) up[i] = i, c[i] = 0;
    for(auto id: chnmx)
    {
        int x = chn[id].first.first, y = chn[id].first.second;
        int val = chn[id].second;
        int lca = LCA(x, y);
        color(x, lca, id);
        color(y, lca, id);
    }
    for(int i = 1; i <= N; i++)
        if(c[i] != 0)
            Matching::addEdge(i, c[i] + N);

    Matching::solve();

    for(int i = 2; i <= N; i++)
    {
        if(Matching::mtc[i] != 0)
        {
            int ch = Matching::mtc[i] - N;
            printf("%d %d %d\n", f[i], i, chn[ch].second);
        }
        else
        {
            int val = 42;
            if(!Matching::edg[i].empty())   val = chn[ Matching::edg[i][0] - N ].second;
            printf("%d %d %d\n", f[i], i, val);
        }
    }


    return 0;
}

Compilation message

minmaxtree.cpp: In function 'int main()':
minmaxtree.cpp:162:13: warning: unused variable 'val' [-Wunused-variable]
         int val = chn[id].second;
             ^~~
minmaxtree.cpp:175:13: warning: unused variable 'val' [-Wunused-variable]
         int val = chn[id].second;
             ^~~
minmaxtree.cpp:125:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &N);
     ~~~~~^~~~~~~~~~
minmaxtree.cpp:129:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d", &x, &y);
         ~~~~~^~~~~~~~~~~~~~~~
minmaxtree.cpp:140:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d\n", &K);
     ~~~~~^~~~~~~~~~~~
minmaxtree.cpp:145:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%c %d%d%d\n", &ch, &x, &y, &val);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 5368 KB Output is correct
2 Correct 6 ms 5376 KB Output is correct
3 Correct 6 ms 5616 KB Output is correct
4 Correct 6 ms 5616 KB Output is correct

Subtask #2
22.0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 169 ms 31340 KB Output is correct
2 Correct 172 ms 31428 KB Output is correct
3 Correct 146 ms 34228 KB Output is correct
4 Correct 173 ms 38748 KB Output is correct
5 Correct 159 ms 38748 KB Output is correct
6 Correct 181 ms 41240 KB Output is correct
7 Correct 163 ms 42884 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 122 ms 42884 KB Output is correct
2 Correct 125 ms 42884 KB Output is correct
3 Correct 116 ms 44940 KB Output is correct
4 Correct 116 ms 47044 KB Output is correct
5 Correct 141 ms 47228 KB Output is correct
6 Correct 144 ms 48984 KB Output is correct
7 Correct 142 ms 49988 KB Output is correct
8 Correct 128 ms 51340 KB Output is correct

Subtask #4
42.0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 5368 KB Output is correct
2 Correct 6 ms 5376 KB Output is correct
3 Correct 6 ms 5616 KB Output is correct
4 Correct 6 ms 5616 KB Output is correct
5 Correct 169 ms 31340 KB Output is correct
6 Correct 172 ms 31428 KB Output is correct
7 Correct 146 ms 34228 KB Output is correct
8 Correct 173 ms 38748 KB Output is correct
9 Correct 159 ms 38748 KB Output is correct
10 Correct 181 ms 41240 KB Output is correct
11 Correct 163 ms 42884 KB Output is correct
12 Correct 122 ms 42884 KB Output is correct
13 Correct 125 ms 42884 KB Output is correct
14 Correct 116 ms 44940 KB Output is correct
15 Correct 116 ms 47044 KB Output is correct
16 Correct 141 ms 47228 KB Output is correct
17 Correct 144 ms 48984 KB Output is correct
18 Correct 142 ms 49988 KB Output is correct
19 Correct 128 ms 51340 KB Output is correct
20 Correct 191 ms 56504 KB Output is correct
21 Correct 150 ms 57332 KB Output is correct
22 Correct 154 ms 59520 KB Output is correct
23 Correct 180 ms 61680 KB Output is correct
24 Correct 184 ms 67228 KB Output is correct
25 Correct 212 ms 70500 KB Output is correct
26 Correct 189 ms 72276 KB Output is correct
27 Correct 189 ms 73712 KB Output is correct
28 Correct 189 ms 74864 KB Output is correct
29 Correct 184 ms 77260 KB Output is correct
30 Correct 172 ms 78520 KB Output is correct
31 Correct 168 ms 80636 KB Output is correct
32 Correct 218 ms 83636 KB Output is correct
33 Correct 178 ms 85288 KB Output is correct
34 Correct 168 ms 87624 KB Output is correct
35 Correct 171 ms 89396 KB Output is correct