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Submission #525820

# Submission time Handle Problem Language Result Execution time Memory
525820 2022-02-13T00:34:44 Z mjhmjh1104 Mountains and Valleys (CCO20_day1problem3) C++17
0 / 25
 3208 ms 108748 KB 
#include <cstdio>
#include <vector>
#include <utility>
#include <algorithm>
using namespace std;
 
int n, m, dp[20][20971520];
vector<int> tree[200006];
vector<pair<int, int>> adj[200006];
 
int f(int x, int y) {
    if (dp[x][y] + 1) return dp[x][y];
    if (!y) return dp[x][y] = 0;
    dp[x][y] = (int)1e9;
    for (auto &i: adj[x]) dp[x][y] = min(dp[x][y], i.second + f(i.first, y & ~(1 << i.first)));
    for (auto &i: tree[x]) dp[x][y] = min(dp[x][y], 1 + f(i, y & ~(1 << i)));
    return dp[x][y];
}
 
int par[200006], sz[200006];
bool cl[200006];
 
int dfs(int x, int prev = -1) {
    par[x] = prev;
    sz[x] = 1;
    for (auto &i: tree[x]) if (i != prev) {
        sz[x] = max(sz[x], dfs(i, x) + 1);
    }
    return sz[x];
}

int lt[5006][5006];
 
void dfs_lt(int x, int y, int dist = 0, int prev = -1) {
    lt[y][x] = dist;
    for (auto &i: tree[x]) if (i != prev) dfs_lt(i, y, dist + 1, x);
}

int dist[200006];
 
int dfs_dist(int x, int prev = -1) {
    vector<int> v;
    int ret = 0;
    dist[x] = 0;
    for (auto &i: tree[x]) if (i != prev) {
        v.push_back(dfs_dist(i, x) + 1);
        ret = max(ret, v.back());
        dist[x] = max(dist[x], dist[i]);
    }
    sort(v.rbegin(), v.rend());
    if (!v.empty()) dist[x] = max(dist[x], v[0]);
    if ((int)v.size() > 1) dist[x] = max(dist[x], v[0] + v[1]);
    return ret;
}
 
int main() {
    scanf("%d%d", &n, &m);
    while (m--) {
        int x, y, w;
        scanf("%d%d%d", &x, &y, &w);
        if (w == 1) {
            tree[x].push_back(y);
            tree[y].push_back(x);
        } else {
            adj[x].push_back({ y, w });
            adj[y].push_back({ x, w });
        }
    }
    /*if (n <= 20) {
        for (int i = 0; i < n; i++) for (int j = 0; j < 1 << n; j++) dp[i][j] = -1;
        int res = (int)1e9;
        for (int i = 0; i < n; i++) res = min(res, f(i, (1 << n) - 1 ^ 1 << i));
        printf("%d", res);
        return 0;
    }*/
    for (int i = 0; i < n; i++) dfs_lt(i, i);
    dfs_dist(0);
    int zero = 2 * (n - 1) - dist[0], one = (int)1e9;
    for (int i = 0; i < n; i++) for (auto &j: adj[i]) if (i < j.first) {
        int curr = j.second + 2 * (n - 1) - lt[i][j.first] - 1;
        dfs(i);
        int x = j.first, pv = -1;
        vector<pair<int, int>> v;
        int y = -1, T = 0;
        dfs_dist(i);
        while (x != -1) {
            for (auto &k: tree[x]) if (k != pv && k != par[x]) {
                if (sz[k]) v.push_back({ sz[k], T });
                y = max(y, dist[k] - 1);
            }
            T++;
            pv = x;
            x = par[x];
        }
        int ans = 0;
        for (int i = 0; i < (int)v.size(); i++) {
            if (i) ans -= v[i].second - v[i - 1].second;
            y = max(y, ans + v[i].first + 1);
            ans = max(ans, v[i].first);
        }
        curr -= y;
        one = min(one, curr);
    }
    printf("%d", min(zero, one));
}

Compilation message

Main.cpp: In function 'int main()':
Main.cpp:57:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   57 |     scanf("%d%d", &n, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~
Main.cpp:60:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   60 |         scanf("%d%d%d", &x, &y, &w);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~

Subtask #1
0.0 / 1.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 9676 KB Output is correct
2 Correct 5 ms 9676 KB Output is correct
3 Correct 5 ms 9676 KB Output is correct
4 Incorrect 5 ms 9676 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #2
0.0 / 2.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 9676 KB Output is correct
2 Correct 5 ms 9676 KB Output is correct
3 Correct 5 ms 9676 KB Output is correct
4 Incorrect 5 ms 9676 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #3
0.0 / 2.0

# Verdict Execution time Memory Grader output
1 Correct 2939 ms 108644 KB Output is correct
2 Correct 2888 ms 108748 KB Output is correct
3 Correct 2879 ms 108392 KB Output is correct
4 Correct 2685 ms 108188 KB Output is correct
5 Correct 2672 ms 108208 KB Output is correct
6 Correct 1096 ms 108236 KB Output is correct
7 Correct 2870 ms 108580 KB Output is correct
8 Correct 3208 ms 108400 KB Output is correct
9 Correct 3034 ms 108568 KB Output is correct
10 Correct 2753 ms 108324 KB Output is correct
11 Correct 2705 ms 108316 KB Output is correct
12 Incorrect 2681 ms 108100 KB Output isn't correct
13 Halted 0 ms 0 KB -

Subtask #4
0.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 9676 KB Output is correct
2 Correct 5 ms 9676 KB Output is correct
3 Correct 5 ms 9676 KB Output is correct
4 Incorrect 5 ms 9676 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #5
0.0 / 2.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 9676 KB Output is correct
2 Correct 5 ms 9676 KB Output is correct
3 Correct 5 ms 9676 KB Output is correct
4 Incorrect 5 ms 9676 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #6
0.0 / 3.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 9676 KB Output is correct
2 Correct 5 ms 9676 KB Output is correct
3 Correct 5 ms 9676 KB Output is correct
4 Incorrect 5 ms 9676 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #7
0.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 9676 KB Output is correct
2 Correct 5 ms 9676 KB Output is correct
3 Correct 5 ms 9676 KB Output is correct
4 Incorrect 5 ms 9676 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #8
0.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 9676 KB Output is correct
2 Correct 5 ms 9676 KB Output is correct
3 Correct 5 ms 9676 KB Output is correct
4 Incorrect 5 ms 9676 KB Output isn't correct
5 Halted 0 ms 0 KB -