Submission #230733

# Submission time Handle Problem Language Result Execution time Memory
230733 2020-05-11T13:42:21 Z emil_physmath Tug of War (BOI15_tug) C++17
100 / 100
2960 ms 6520 KB
#include <unordered_set>
#include <algorithm>
#include <iostream>
#include <bitset>
#include <vector>
#include <set>
using namespace std;
const int maxN = 30'000;
struct Jmp
{
    int to, wei;
    operator int&() { return to; }
};

vector<Jmp> jmp[2 * maxN];
Jmp par[2 * maxN];
bool used[2 * maxN], cyc[2 * maxN];

pair<int, Jmp> DFS(int v, int& nodes, int& edges)
{
    static unordered_set<int> st;
    st.insert(v);
    ++nodes;
    used[v] = true;
    pair<int, Jmp> ret = {-1, {-1, -1}};
    edges += jmp[v].size();
    for (int i = 0; i < jmp[v].size(); ++i)
    {
        Jmp to = jmp[v][i];
        if (!used[to])
        {
            par[to] = {v, to.wei};
            pair<int, Jmp> x = DFS(to, nodes, edges);
            if (x.first != -1)
                ret = x;
            if (i + 1 < jmp[v].size() && jmp[v][i + 1] == to)
                ret = {to, {v, jmp[v][i + 1].wei}};
        }
        else if (to != par[v] && st.count(to))
            ret = {v, to};
    }
    st.erase(v);
    return ret;
}
void SolveSub(int v, int p, int& ans)
{
    for (Jmp to: jmp[v])
        if (to != p && !cyc[to])
        {
            ans += to.wei * (to % 2 ? 1 : -1);
            SolveSub(to, v, ans);
        }
}
pair<int, int> Solve(int v)
{
    int nodes = 0, edges = 0;
    par[v] = {-1, -1};
    pair<int, Jmp> p = DFS(v, nodes, edges);
    edges /= 2;
    if (edges != nodes)
    {
        cout << "NO";
        exit(0);
    }
    pair<int, int> ans;
    for (int u = p.first; u != p.second; u = par[u])
    {
        ans.first += par[u].wei * (u % 2 ? 1 : -1);
        ans.second += par[u].wei * (par[u] % 2 ? 1 : -1);
    }
    ans.first += p.second.wei * (p.second % 2 ? 1 : -1);
    ans.second += p.second.wei * (p.first % 2 ? 1 : -1);
    vector<int> cycle;
    while (true)
    {
        cycle.push_back(p.first);
        if (p.first == p.second) break;
        p.first = par[p.first];
    }
    for (int u: cycle)
        cyc[u] = true;
    int ans0 = 0;
    for (int u: cycle)
        SolveSub(u, -1, ans0);
    ans.second += ans0;
    ans.first += ans0;
    return ans;
}
int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    int n, k;
    cin >> n >> k;
    for (int i = 0; i < 2 * n; ++i)
    {
        int l, r, s;
        cin >> l >> r >> s;
        --l; --r;
        jmp[2 * l].push_back({2 * r + 1, s});
        jmp[2 * r + 1].push_back({2 * l, s});
#ifdef MANSON
        cout << "(" << 2 * l << ", " << 2 * r + 1 << ": " << s << ")\n";
#endif
    }
    for (int i = 0; i < 2 * n; ++i)
        sort(jmp[i].begin(), jmp[i].end());
    vector<pair<int, int>> a;
    for (int i = 0; i < 2 * n; ++i)
        if (!used[i])
        {
            a.push_back(Solve(i));
#ifdef MANSON
            cerr << a.back().first << ", " << a.back().second << '\n';
#endif
        }
    bitset<2 * 20 * maxN + 1> dp;
    dp.set(20 * n);
    for (int i = 0; i < a.size(); ++i)
    {
        int x = a[i].first, y = a[i].second;
        dp = (x > 0 ? dp << x : dp >> -x) | (y > 0 ? dp << y : dp >> -y);
    }
    int ans = 20 * n;
    for (int i = 0; i <= 2 * 20 * n; ++i)
        if (dp[i])
            ans = min(ans, abs(20 * n - i));
    cout << (ans <= k ? "YES" : "NO");
}

Compilation message

tug.cpp: In function 'std::pair<int, Jmp> DFS(int, int&, int&)':
tug.cpp:27:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < jmp[v].size(); ++i)
                     ~~^~~~~~~~~~~~~~~
tug.cpp:36:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             if (i + 1 < jmp[v].size() && jmp[v][i + 1] == to)
                 ~~~~~~^~~~~~~~~~~~~~~
tug.cpp: In function 'int main()':
tug.cpp:119:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < a.size(); ++i)
                     ~~^~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 7 ms 2432 KB Output is correct
2 Correct 7 ms 2432 KB Output is correct
3 Correct 7 ms 2560 KB Output is correct
4 Correct 7 ms 2560 KB Output is correct
5 Correct 7 ms 2560 KB Output is correct
6 Correct 7 ms 2432 KB Output is correct
7 Correct 7 ms 2432 KB Output is correct
8 Correct 7 ms 2560 KB Output is correct
9 Correct 7 ms 2560 KB Output is correct
10 Correct 7 ms 2432 KB Output is correct
11 Correct 7 ms 2432 KB Output is correct
12 Correct 7 ms 2432 KB Output is correct
13 Correct 7 ms 2432 KB Output is correct
14 Correct 7 ms 2432 KB Output is correct
15 Correct 7 ms 2560 KB Output is correct
16 Correct 7 ms 2432 KB Output is correct
17 Correct 7 ms 2432 KB Output is correct
18 Correct 7 ms 2432 KB Output is correct
19 Correct 7 ms 2432 KB Output is correct
20 Correct 7 ms 2432 KB Output is correct
21 Correct 5 ms 1792 KB Output is correct
22 Correct 6 ms 2432 KB Output is correct
23 Correct 7 ms 2432 KB Output is correct
24 Correct 7 ms 2432 KB Output is correct
25 Correct 7 ms 2432 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 7 ms 2432 KB Output is correct
2 Correct 7 ms 2432 KB Output is correct
3 Correct 7 ms 2560 KB Output is correct
4 Correct 7 ms 2560 KB Output is correct
5 Correct 7 ms 2560 KB Output is correct
6 Correct 7 ms 2432 KB Output is correct
7 Correct 7 ms 2432 KB Output is correct
8 Correct 7 ms 2560 KB Output is correct
9 Correct 7 ms 2560 KB Output is correct
10 Correct 7 ms 2432 KB Output is correct
11 Correct 7 ms 2432 KB Output is correct
12 Correct 7 ms 2432 KB Output is correct
13 Correct 7 ms 2432 KB Output is correct
14 Correct 7 ms 2432 KB Output is correct
15 Correct 7 ms 2560 KB Output is correct
16 Correct 7 ms 2432 KB Output is correct
17 Correct 7 ms 2432 KB Output is correct
18 Correct 7 ms 2432 KB Output is correct
19 Correct 7 ms 2432 KB Output is correct
20 Correct 7 ms 2432 KB Output is correct
21 Correct 5 ms 1792 KB Output is correct
22 Correct 6 ms 2432 KB Output is correct
23 Correct 7 ms 2432 KB Output is correct
24 Correct 7 ms 2432 KB Output is correct
25 Correct 7 ms 2432 KB Output is correct
26 Correct 202 ms 2808 KB Output is correct
27 Correct 34 ms 2688 KB Output is correct
28 Correct 211 ms 2688 KB Output is correct
29 Correct 35 ms 2688 KB Output is correct
30 Correct 208 ms 2808 KB Output is correct
31 Correct 34 ms 2688 KB Output is correct
32 Correct 204 ms 2772 KB Output is correct
33 Correct 34 ms 2688 KB Output is correct
34 Correct 21 ms 2688 KB Output is correct
35 Correct 35 ms 2688 KB Output is correct
36 Correct 201 ms 2812 KB Output is correct
37 Correct 34 ms 2688 KB Output is correct
38 Correct 205 ms 2808 KB Output is correct
39 Correct 34 ms 2688 KB Output is correct
40 Correct 203 ms 2808 KB Output is correct
41 Correct 35 ms 2688 KB Output is correct
42 Correct 201 ms 2688 KB Output is correct
43 Correct 34 ms 2688 KB Output is correct
44 Correct 206 ms 2688 KB Output is correct
45 Correct 35 ms 2688 KB Output is correct
46 Correct 208 ms 2788 KB Output is correct
47 Correct 7 ms 2048 KB Output is correct
48 Correct 106 ms 2688 KB Output is correct
49 Correct 108 ms 2808 KB Output is correct
50 Correct 209 ms 2688 KB Output is correct
51 Correct 203 ms 2688 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 650 ms 3752 KB Output is correct
2 Correct 14 ms 2816 KB Output is correct
3 Correct 696 ms 3724 KB Output is correct
4 Correct 14 ms 2688 KB Output is correct
5 Correct 661 ms 3728 KB Output is correct
6 Correct 14 ms 2816 KB Output is correct
7 Correct 654 ms 3752 KB Output is correct
8 Correct 14 ms 2816 KB Output is correct
9 Correct 657 ms 3752 KB Output is correct
10 Correct 14 ms 2816 KB Output is correct
11 Correct 667 ms 3752 KB Output is correct
12 Correct 14 ms 2816 KB Output is correct
13 Correct 654 ms 3752 KB Output is correct
14 Correct 640 ms 3840 KB Output is correct
15 Correct 14 ms 2816 KB Output is correct
16 Correct 662 ms 3724 KB Output is correct
17 Correct 15 ms 2816 KB Output is correct
18 Correct 661 ms 3724 KB Output is correct
19 Correct 14 ms 2816 KB Output is correct
20 Correct 661 ms 3752 KB Output is correct
21 Correct 16 ms 3328 KB Output is correct
22 Correct 431 ms 3832 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 7 ms 2432 KB Output is correct
2 Correct 7 ms 2432 KB Output is correct
3 Correct 7 ms 2560 KB Output is correct
4 Correct 7 ms 2560 KB Output is correct
5 Correct 7 ms 2560 KB Output is correct
6 Correct 7 ms 2432 KB Output is correct
7 Correct 7 ms 2432 KB Output is correct
8 Correct 7 ms 2560 KB Output is correct
9 Correct 7 ms 2560 KB Output is correct
10 Correct 7 ms 2432 KB Output is correct
11 Correct 7 ms 2432 KB Output is correct
12 Correct 7 ms 2432 KB Output is correct
13 Correct 7 ms 2432 KB Output is correct
14 Correct 7 ms 2432 KB Output is correct
15 Correct 7 ms 2560 KB Output is correct
16 Correct 7 ms 2432 KB Output is correct
17 Correct 7 ms 2432 KB Output is correct
18 Correct 7 ms 2432 KB Output is correct
19 Correct 7 ms 2432 KB Output is correct
20 Correct 7 ms 2432 KB Output is correct
21 Correct 5 ms 1792 KB Output is correct
22 Correct 6 ms 2432 KB Output is correct
23 Correct 7 ms 2432 KB Output is correct
24 Correct 7 ms 2432 KB Output is correct
25 Correct 7 ms 2432 KB Output is correct
26 Correct 202 ms 2808 KB Output is correct
27 Correct 34 ms 2688 KB Output is correct
28 Correct 211 ms 2688 KB Output is correct
29 Correct 35 ms 2688 KB Output is correct
30 Correct 208 ms 2808 KB Output is correct
31 Correct 34 ms 2688 KB Output is correct
32 Correct 204 ms 2772 KB Output is correct
33 Correct 34 ms 2688 KB Output is correct
34 Correct 21 ms 2688 KB Output is correct
35 Correct 35 ms 2688 KB Output is correct
36 Correct 201 ms 2812 KB Output is correct
37 Correct 34 ms 2688 KB Output is correct
38 Correct 205 ms 2808 KB Output is correct
39 Correct 34 ms 2688 KB Output is correct
40 Correct 203 ms 2808 KB Output is correct
41 Correct 35 ms 2688 KB Output is correct
42 Correct 201 ms 2688 KB Output is correct
43 Correct 34 ms 2688 KB Output is correct
44 Correct 206 ms 2688 KB Output is correct
45 Correct 35 ms 2688 KB Output is correct
46 Correct 208 ms 2788 KB Output is correct
47 Correct 7 ms 2048 KB Output is correct
48 Correct 106 ms 2688 KB Output is correct
49 Correct 108 ms 2808 KB Output is correct
50 Correct 209 ms 2688 KB Output is correct
51 Correct 203 ms 2688 KB Output is correct
52 Correct 650 ms 3752 KB Output is correct
53 Correct 14 ms 2816 KB Output is correct
54 Correct 696 ms 3724 KB Output is correct
55 Correct 14 ms 2688 KB Output is correct
56 Correct 661 ms 3728 KB Output is correct
57 Correct 14 ms 2816 KB Output is correct
58 Correct 654 ms 3752 KB Output is correct
59 Correct 14 ms 2816 KB Output is correct
60 Correct 657 ms 3752 KB Output is correct
61 Correct 14 ms 2816 KB Output is correct
62 Correct 667 ms 3752 KB Output is correct
63 Correct 14 ms 2816 KB Output is correct
64 Correct 654 ms 3752 KB Output is correct
65 Correct 640 ms 3840 KB Output is correct
66 Correct 14 ms 2816 KB Output is correct
67 Correct 662 ms 3724 KB Output is correct
68 Correct 15 ms 2816 KB Output is correct
69 Correct 661 ms 3724 KB Output is correct
70 Correct 14 ms 2816 KB Output is correct
71 Correct 661 ms 3752 KB Output is correct
72 Correct 16 ms 3328 KB Output is correct
73 Correct 431 ms 3832 KB Output is correct
74 Correct 2948 ms 6136 KB Output is correct
75 Correct 166 ms 5756 KB Output is correct
76 Correct 2960 ms 6136 KB Output is correct
77 Correct 156 ms 5752 KB Output is correct
78 Correct 2891 ms 6160 KB Output is correct
79 Correct 2864 ms 6140 KB Output is correct
80 Correct 163 ms 5880 KB Output is correct
81 Correct 159 ms 5880 KB Output is correct
82 Correct 2891 ms 6136 KB Output is correct
83 Correct 2857 ms 6136 KB Output is correct
84 Correct 146 ms 5752 KB Output is correct
85 Correct 2921 ms 6136 KB Output is correct
86 Correct 152 ms 5752 KB Output is correct
87 Correct 2843 ms 6136 KB Output is correct
88 Correct 149 ms 6008 KB Output is correct
89 Correct 2869 ms 6136 KB Output is correct
90 Correct 151 ms 5752 KB Output is correct
91 Correct 2934 ms 6136 KB Output is correct
92 Correct 149 ms 5752 KB Output is correct
93 Correct 2922 ms 6136 KB Output is correct
94 Correct 38 ms 4728 KB Output is correct
95 Correct 1541 ms 6520 KB Output is correct
96 Correct 1474 ms 6272 KB Output is correct
97 Correct 2910 ms 6136 KB Output is correct
98 Correct 2960 ms 6136 KB Output is correct