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Submission #257042

# Submission time Handle Problem Language Result Execution time Memory
257042 2020-08-03T14:36:06 Z Bruteforceman Aesthetic (NOI20_aesthetic) C++11
35 / 100
 2000 ms 75000 KB 
#include <bits/stdc++.h>
using namespace std;
const int maxn = 3e5 + 10;
const int logn = 19;
const long long inf = 1e16;
int anc[logn + 1][maxn];
int l[maxn], r[maxn], w[maxn];
vector <int> g[maxn], t[maxn];
long long ans[maxn];
int dep[maxn];
int n, m;

struct data {
  long long dist;
  int node;
  data (long long dist, int node) : dist(dist), node(node) {}
  data () {}
  bool operator < (data d) const {
    return dist > d.dist;
  }
};

vector <long long> dijstra(int root) {
  priority_queue <data> Q;

  vector <long long> dist (n, inf);
  Q.emplace(0, root);
  dist[root] = 0;
  while(!Q.empty()) {
    int node = Q.top().node;
    long long var = Q.top().dist;
    Q.pop();
    if(var != dist[node]) continue;
    for(int e : g[node]) {
      int x = l[e] ^ r[e] ^ node;
      if(w[e] + dist[node] < dist[x]) {
        dist[x] = w[e] + dist[node];
        Q.emplace(dist[x], x);
      }
    }
  }
  return dist;
}
void dfs(int x) {
  for(int i = 1; i <= logn; i++) {
    anc[i][x] = anc[i - 1][anc[i - 1][x]];
  }
  for(int i : t[x]) {
    dep[i] = 1 + dep[x];
    anc[0][i] = x;
    dfs(i);
  }
}
int lca(int x, int y) {
  if(dep[x] > dep[y]) swap(x, y);
  for(int i = logn; i >= 0; i--) {
    if(dep[y] - (1 << i) >= dep[x]) {
      y = anc[i][y];
    }
  }
  if(x == y) return x;
  for(int i = logn; i >= 0; i--) {
    if(anc[i][x] != anc[i][y]) {
      x = anc[i][x];
      y = anc[i][y];
    }
  }
  return anc[0][x];
}
int main() {
  scanf("%d %d", &n, &m);
  for(int i = 0; i < m; i++) {
    scanf("%d %d %d", &l[i], &r[i], &w[i]);
    l[i] -= 1;
    r[i] -= 1;
    g[l[i]].push_back(i);
    g[r[i]].push_back(i);
  }
  vector <long long> forward = dijstra(0);
  vector <int> par (n);
  for(int i = 1; i < n; i++) {
    for(int e : g[i]) {
      int x = l[e] ^ r[e] ^ i;
      if(forward[x] + w[e] == forward[i]) {
        par[i] = e;
        t[x].push_back(i);
        break;
      }
    }
  }
  dfs(0);
  vector <long long> backward = dijstra(n - 1);
  int cur = n - 1;
  vector <bool> onPath (m);
  vector <int> id (n);
  while(cur != 0) {
    int e = par[cur];
    onPath[e] = true;
    cur = anc[0][cur];
    id[dep[cur]] = e;
  }
  for(int i = 0; i < m; i++) ans[i] = inf;
  vector <vector <pair <int, int>>> cont (n); 
  for(int i = 0; i < m; i++) {
    if(onPath[i]) continue;
    ans[i] = forward[n - 1];
    int p = lca(l[i], n - 1);
    int q = lca(r[i], n - 1);
    if(dep[p] > dep[q])  {
      swap(p, q);
      swap(l[i], r[i]);
    }
    long long cost = w[i] + forward[l[i]] + backward[r[i]];
    for(int x = dep[p]; x < dep[q]; x++) {
      ans[id[x]] = min(ans[id[x]], cost);
    }
    // cont[dep[p]].emplace_back(cost, 1);
    // cont[dep[q]].emplace_back(cost, -1);
  }
  /* multiset <long long> bst;
  for(int i = 0; i < dep[n - 1]; i++) {
    for(auto j : cont[i]) {
      if(j.second == 1) bst.insert(j.first);
      else bst.erase(bst.find(j.first));
    }
    ans[id[i]] = bst.empty() ? inf : *bst.begin();
    cout << id[i] << ' ';
  }
  */
  int mx = w[m - 1];
  long long res = 0;
  for(int i = m - 2; i >= 0; i--) {
    long long p = forward[l[i]] + mx + w[i] + backward[r[i]];
    long long q = forward[r[i]] + mx + w[i] + backward[l[i]];
    res = max(res, min({ans[i], p, q}));
    mx = max(mx, w[i]);
  }
  printf("%lld\n", res);
  return 0;
}

Compilation message

Aesthetic.cpp: In function 'int main()':
Aesthetic.cpp:71:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d", &n, &m);
   ~~~~~^~~~~~~~~~~~~~~~~
Aesthetic.cpp:73:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d %d", &l[i], &r[i], &w[i]);
     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 14592 KB Output is correct
2 Correct 9 ms 14592 KB Output is correct
3 Correct 9 ms 14592 KB Output is correct
4 Correct 9 ms 14592 KB Output is correct
5 Correct 9 ms 14592 KB Output is correct
6 Correct 9 ms 14592 KB Output is correct
7 Correct 9 ms 14592 KB Output is correct
8 Correct 8 ms 14592 KB Output is correct

Subtask #2
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 14592 KB Output is correct
2 Correct 9 ms 14592 KB Output is correct
3 Correct 9 ms 14592 KB Output is correct
4 Correct 9 ms 14592 KB Output is correct
5 Correct 9 ms 14592 KB Output is correct
6 Correct 9 ms 14592 KB Output is correct
7 Correct 9 ms 14592 KB Output is correct
8 Correct 8 ms 14592 KB Output is correct
9 Correct 11 ms 14848 KB Output is correct
10 Correct 11 ms 14848 KB Output is correct
11 Correct 12 ms 14848 KB Output is correct
12 Correct 11 ms 14848 KB Output is correct
13 Correct 11 ms 14720 KB Output is correct
14 Correct 11 ms 14720 KB Output is correct
15 Correct 10 ms 14720 KB Output is correct
16 Correct 10 ms 14720 KB Output is correct

Subtask #3
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 1177 ms 73592 KB Output is correct
2 Correct 1037 ms 73848 KB Output is correct
3 Correct 1279 ms 73068 KB Output is correct
4 Correct 1242 ms 73104 KB Output is correct
5 Correct 1420 ms 73208 KB Output is correct
6 Correct 1254 ms 74808 KB Output is correct
7 Correct 1219 ms 74360 KB Output is correct
8 Correct 1268 ms 74860 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1366 ms 74872 KB Output is correct
2 Correct 1225 ms 73932 KB Output is correct
3 Correct 1066 ms 73592 KB Output is correct
4 Correct 1016 ms 75000 KB Output is correct
5 Correct 1205 ms 73592 KB Output is correct
6 Correct 1033 ms 73848 KB Output is correct
7 Correct 1210 ms 73720 KB Output is correct
8 Correct 1283 ms 74132 KB Output is correct

Subtask #5
0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 869 ms 57948 KB Output is correct
2 Correct 336 ms 68624 KB Output is correct
3 Correct 455 ms 41080 KB Output is correct
4 Correct 501 ms 40952 KB Output is correct
5 Correct 483 ms 41080 KB Output is correct
6 Correct 428 ms 41080 KB Output is correct
7 Correct 421 ms 41080 KB Output is correct
8 Correct 434 ms 41080 KB Output is correct
9 Correct 424 ms 41080 KB Output is correct
10 Correct 434 ms 41080 KB Output is correct
11 Correct 426 ms 41080 KB Output is correct
12 Correct 858 ms 57212 KB Output is correct
13 Correct 450 ms 40952 KB Output is correct
14 Execution timed out 2098 ms 63480 KB Time limit exceeded
15 Halted 0 ms 0 KB -

Subtask #6
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 869 ms 57948 KB Output is correct
2 Correct 336 ms 68624 KB Output is correct
3 Correct 455 ms 41080 KB Output is correct
4 Correct 501 ms 40952 KB Output is correct
5 Correct 483 ms 41080 KB Output is correct
6 Correct 428 ms 41080 KB Output is correct
7 Correct 421 ms 41080 KB Output is correct
8 Correct 434 ms 41080 KB Output is correct
9 Correct 424 ms 41080 KB Output is correct
10 Correct 434 ms 41080 KB Output is correct
11 Correct 426 ms 41080 KB Output is correct
12 Correct 858 ms 57212 KB Output is correct
13 Correct 450 ms 40952 KB Output is correct
14 Execution timed out 2098 ms 63480 KB Time limit exceeded
15 Halted 0 ms 0 KB -

Subtask #7
0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 14592 KB Output is correct
2 Correct 9 ms 14592 KB Output is correct
3 Correct 9 ms 14592 KB Output is correct
4 Correct 9 ms 14592 KB Output is correct
5 Correct 9 ms 14592 KB Output is correct
6 Correct 9 ms 14592 KB Output is correct
7 Correct 9 ms 14592 KB Output is correct
8 Correct 8 ms 14592 KB Output is correct
9 Correct 11 ms 14848 KB Output is correct
10 Correct 11 ms 14848 KB Output is correct
11 Correct 12 ms 14848 KB Output is correct
12 Correct 11 ms 14848 KB Output is correct
13 Correct 11 ms 14720 KB Output is correct
14 Correct 11 ms 14720 KB Output is correct
15 Correct 10 ms 14720 KB Output is correct
16 Correct 10 ms 14720 KB Output is correct
17 Correct 1177 ms 73592 KB Output is correct
18 Correct 1037 ms 73848 KB Output is correct
19 Correct 1279 ms 73068 KB Output is correct
20 Correct 1242 ms 73104 KB Output is correct
21 Correct 1420 ms 73208 KB Output is correct
22 Correct 1254 ms 74808 KB Output is correct
23 Correct 1219 ms 74360 KB Output is correct
24 Correct 1268 ms 74860 KB Output is correct
25 Correct 1366 ms 74872 KB Output is correct
26 Correct 1225 ms 73932 KB Output is correct
27 Correct 1066 ms 73592 KB Output is correct
28 Correct 1016 ms 75000 KB Output is correct
29 Correct 1205 ms 73592 KB Output is correct
30 Correct 1033 ms 73848 KB Output is correct
31 Correct 1210 ms 73720 KB Output is correct
32 Correct 1283 ms 74132 KB Output is correct
33 Correct 869 ms 57948 KB Output is correct
34 Correct 336 ms 68624 KB Output is correct
35 Correct 455 ms 41080 KB Output is correct
36 Correct 501 ms 40952 KB Output is correct
37 Correct 483 ms 41080 KB Output is correct
38 Correct 428 ms 41080 KB Output is correct
39 Correct 421 ms 41080 KB Output is correct
40 Correct 434 ms 41080 KB Output is correct
41 Correct 424 ms 41080 KB Output is correct
42 Correct 434 ms 41080 KB Output is correct
43 Correct 426 ms 41080 KB Output is correct
44 Correct 858 ms 57212 KB Output is correct
45 Correct 450 ms 40952 KB Output is correct
46 Execution timed out 2098 ms 63480 KB Time limit exceeded
47 Halted 0 ms 0 KB -