Submission #525821

# Submission time Handle Problem Language Result Execution time Memory
525821 2022-02-13T00:38:02 Z mjhmjh1104 Mountains and Valleys (CCO20_day1problem3) C++17
0 / 25
3231 ms 108620 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 = -(int)1e9;
        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);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~
# 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 9732 KB Output is correct
4 Correct 5 ms 9676 KB Output is correct
5 Incorrect 5 ms 9676 KB Output isn't correct
6 Halted 0 ms 0 KB -
# 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 9732 KB Output is correct
4 Correct 5 ms 9676 KB Output is correct
5 Incorrect 5 ms 9676 KB Output isn't correct
6 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 3132 ms 108580 KB Output is correct
2 Correct 2997 ms 108620 KB Output is correct
3 Correct 2929 ms 108396 KB Output is correct
4 Correct 2787 ms 108272 KB Output is correct
5 Correct 2644 ms 108212 KB Output is correct
6 Correct 1097 ms 108076 KB Output is correct
7 Correct 2871 ms 108616 KB Output is correct
8 Correct 3231 ms 108496 KB Output is correct
9 Correct 3010 ms 108572 KB Output is correct
10 Correct 2684 ms 108276 KB Output is correct
11 Correct 2721 ms 108320 KB Output is correct
12 Incorrect 2634 ms 108100 KB Output isn't correct
13 Halted 0 ms 0 KB -
# 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 9732 KB Output is correct
4 Correct 5 ms 9676 KB Output is correct
5 Incorrect 5 ms 9676 KB Output isn't correct
6 Halted 0 ms 0 KB -
# 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 9732 KB Output is correct
4 Correct 5 ms 9676 KB Output is correct
5 Incorrect 5 ms 9676 KB Output isn't correct
6 Halted 0 ms 0 KB -
# 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 9732 KB Output is correct
4 Correct 5 ms 9676 KB Output is correct
5 Incorrect 5 ms 9676 KB Output isn't correct
6 Halted 0 ms 0 KB -
# 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 9732 KB Output is correct
4 Correct 5 ms 9676 KB Output is correct
5 Incorrect 5 ms 9676 KB Output isn't correct
6 Halted 0 ms 0 KB -
# 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 9732 KB Output is correct
4 Correct 5 ms 9676 KB Output is correct
5 Incorrect 5 ms 9676 KB Output isn't correct
6 Halted 0 ms 0 KB -