Submission #886744

#	Time	Username	Problem	Language	Result	Execution time	Memory
886744		DrAymeinstein	Training (IOI07_training)	C++17	100 / 100	28 ms	97116 KiB

training

#include <iostream>
#include <vector>
#include <algorithm>
#include <cstring>

#define N 1005
#define BIT(x, i) ((x >> i) & 1)

using namespace std;

vector<int> a[N];

class edge {
public:
    int u, v, k;
};

vector<edge> c[N], add;

long long n, m, i, u, v, sum, f[N], g[N], p[N], h[N], k, num[N][N], w[11], w2[11][11], dp[N][11][1024], nchild[N];

void dfs(int u) {
    for (int i = 0; i < a[u].size(); i++) {
        int v = a[u][i];
        if (v != p[u]) h[v] = h[u] + 1, p[v] = u, dfs(v);
    }
}

void opt(long long& a, long long b) {
    a = max(a, b);
}

int LCA(int u, int v) {
    while (h[u] > h[v]) {
        u = p[u];
    }

    while (h[v] > h[u]) {
        v = p[v];
    }

    while (u != v) {
        u = p[u], v = p[v];
    }

    return u;
}

int nearest(int u, int v) {
    while (p[u] != v) {
        u = p[u];
    }

    return u;
}

long long climb(int u, int v) {
    long long res = 0, last;
    res += f[u];
    last = u;
    u = p[u];

    while (u != v) {
        res += dp[u][nchild[u] - 1][((1 << nchild[u]) - 1) ^ (1 << num[u][last])];
        last = u;
        u = p[u];
    }

    return res;
}

void DFS(int u) {
    int i, j, tt;

    for (int i = 0; i < a[u].size(); i++) {
        int v = a[u][i];
        if (v != p[u]) {
            DFS(v);
        }
    }

    for (int v : a[u]) {
        if (v != p[u]) {
            g[nchild[u]] = f[v], num[u][v] = nchild[u]++;
        }
    }

    memset(w, 0, sizeof(w));
    memset(w2, 0, sizeof(w2));

    for (int i = 0; i < c[u].size(); i++) {
        edge x = c[u][i];
        int v1 = x.u, v2 = x.v, k = x.k, tg1, tg2;
        long long sum, sum1, sum2;
        if (v2 == u) {
            tg1 = num[u][nearest(v1, u)];
            opt(w[tg1], climb(v1, u) + k);
        }
        else {
            tg1 = num[u][nearest(v1, u)];
            sum1 = climb(v1, u);
            tg2 = num[u][nearest(v2, u)];
            sum2 = climb(v2, u);
            opt(w2[tg1][tg2], sum1 + sum2 + k);
            opt(w2[tg2][tg1], sum1 + sum2 + k);
        }
    }

    if (nchild[u] == 0) return;
    dp[u][0][0] = 0;
    dp[u][0][1] = max(w[0], g[0]);
    for (i = 1; i < nchild[u]; i++) {
        for (tt = 0; tt < (1 << i); tt++) {
            opt(dp[u][i][tt], dp[u][i - 1][tt]);
            opt(dp[u][i][tt | (1 << i)], dp[u][i - 1][tt] + max(g[i], w[i]));
            for (j = 0; j < i; j++)
                if (BIT(tt, j) == 0) {
                    opt(dp[u][i][(tt | (1 << i)) | (1 << j)], dp[u][i - 1][tt] + max(w2[i][j], g[i] + g[j]));
                }
        }
    }
    f[u] = dp[u][nchild[u] - 1][(1 << nchild[u]) - 1];
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    cin >> n >> m;
    for (int i = m; i >= 1; i--) {
        cin >> u >> v >> k;
        edge tg = { u, v, k };
        if (k == 0) a[u].push_back(v), a[v].push_back(u);
        else add.push_back(tg), sum += k;
    }

    dfs(1);
    for (i = 0; i < add.size(); i++) {
        edge x = add[i];
        int u = x.u, v = x.v, k = x.k, p = LCA(u, v);
        if (h[u] < h[v]) swap(u, v);
        if ((h[u] + h[v] - 2 * h[p]) & 1) continue;
        edge tg = { u, v, k };
        c[p].push_back(tg);
    }

    DFS(1);
    cout << sum - f[1];

    return 0;
}

Compilation message (stderr)

training.cpp: In function 'void dfs(int)':
training.cpp:23:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   23 |     for (int i = 0; i < a[u].size(); i++) {
      |                     ~~^~~~~~~~~~~~~
training.cpp: In function 'void DFS(int)':
training.cpp:75:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   75 |     for (int i = 0; i < a[u].size(); i++) {
      |                     ~~^~~~~~~~~~~~~
training.cpp:91:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<edge>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   91 |     for (int i = 0; i < c[u].size(); i++) {
      |                     ~~^~~~~~~~~~~~~
training.cpp:94:19: warning: unused variable 'sum' [-Wunused-variable]
   94 |         long long sum, sum1, sum2;
      |                   ^~~
training.cpp: In function 'int main()':
training.cpp:132:21: warning: narrowing conversion of 'u' from 'long long int' to 'int' [-Wnarrowing]
  132 |         edge tg = { u, v, k };
      |                     ^
training.cpp:132:24: warning: narrowing conversion of 'v' from 'long long int' to 'int' [-Wnarrowing]
  132 |         edge tg = { u, v, k };
      |                        ^
training.cpp:132:27: warning: narrowing conversion of 'k' from 'long long int' to 'int' [-Wnarrowing]
  132 |         edge tg = { u, v, k };
      |                           ^
training.cpp:138:19: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<edge>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  138 |     for (i = 0; i < add.size(); i++) {
      |                 ~~^~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 7 / 7
• Subtask 5: 9 / 9
• Subtask 6: 9 / 9
• Subtask 7: 9 / 9
• Subtask 8: 9 / 9
• Subtask 9: 9 / 9
• Subtask 10: 9 / 9
• Subtask 11: 9 / 9