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답안 #257083

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
257083 2020-08-03T15:19:27 Z Bruteforceman Aesthetic (NOI20_aesthetic) C++11
51 / 100
 1520 ms 80400 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];
}
long long prop[maxn * 4];
void update(int x, int y, long long val, int c = 1, int b = 0, int e = n) {
  if(x <= b && e <= y) {
    prop[c] = min(prop[c], val);
    return ;
  }
  if(y < b || e < x) return ;
  int m = (b + e) >> 1;
  int l = c << 1;
  int r = l + 1;
  update(x, y, val, l, b, m);
  update(x, y, val, r, m + 1, e);
}
long long get(int x, int c = 1, int b = 0, int e = n) {
  if(b == e) return prop[c];
  int m = (b + e) >> 1;
  int l = c << 1;
  int r = l + 1;
  if(x <= m) return min(prop[c], get(x, l, b, m));
  else return min(prop[c], get(x, r, m + 1, e));
}
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);
  }
  for(int i = 0; i <= 4 * (n + 1); i++) prop[i] = inf;
  vector <long long> forward = dijstra(0);
  vector <long long> backward = dijstra(n - 1);

  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);
  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;
  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);
    }
    long long cost = min(w[i] + forward[l[i]] + backward[r[i]], 
        w[i] + forward[r[i]] + backward[l[i]]);
    if(dep[p] < dep[q]) {
      update(dep[p], dep[q] - 1, cost);
    }
  }
  for(int i = 0; i < dep[n - 1]; i++) {
    ans[id[i]] = get(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:92:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d", &n, &m);
   ~~~~~^~~~~~~~~~~~~~~~~
Aesthetic.cpp:94:10: 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

# 결과 실행 시간 메모리 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 12 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 10 ms 14592 KB Output is correct
8 Correct 9 ms 14592 KB Output is correct

Subtask #2
8.0 / 8.0

# 결과 실행 시간 메모리 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 12 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 10 ms 14592 KB Output is correct
8 Correct 9 ms 14592 KB Output is correct
9 Correct 12 ms 14972 KB Output is correct
10 Correct 11 ms 14848 KB Output is correct
11 Correct 11 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 11 ms 14720 KB Output is correct
16 Correct 11 ms 14720 KB Output is correct

Subtask #3
7.0 / 7.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1234 ms 79128 KB Output is correct
2 Correct 1202 ms 79644 KB Output is correct
3 Correct 1286 ms 78668 KB Output is correct
4 Correct 1297 ms 78968 KB Output is correct
5 Correct 1387 ms 78892 KB Output is correct
6 Correct 1493 ms 80332 KB Output is correct
7 Correct 1405 ms 79992 KB Output is correct
8 Correct 1253 ms 80376 KB Output is correct

Subtask #4
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1346 ms 80304 KB Output is correct
2 Correct 1520 ms 79408 KB Output is correct
3 Correct 1407 ms 79284 KB Output is correct
4 Correct 1175 ms 80400 KB Output is correct
5 Correct 1240 ms 79224 KB Output is correct
6 Correct 1181 ms 79480 KB Output is correct
7 Correct 1484 ms 79424 KB Output is correct
8 Correct 1450 ms 79736 KB Output is correct

Subtask #5
16.0 / 16.0

# 결과 실행 시간 메모리 Grader output
1 Correct 914 ms 62936 KB Output is correct
2 Correct 347 ms 73976 KB Output is correct
3 Correct 438 ms 45304 KB Output is correct
4 Correct 427 ms 45048 KB Output is correct
5 Correct 430 ms 45236 KB Output is correct
6 Correct 462 ms 45176 KB Output is correct
7 Correct 509 ms 45176 KB Output is correct
8 Correct 444 ms 45304 KB Output is correct
9 Correct 419 ms 45048 KB Output is correct
10 Correct 429 ms 45304 KB Output is correct
11 Correct 457 ms 45176 KB Output is correct
12 Correct 859 ms 62200 KB Output is correct
13 Correct 419 ms 45176 KB Output is correct
14 Correct 263 ms 68472 KB Output is correct
15 Correct 247 ms 65272 KB Output is correct
16 Correct 829 ms 60992 KB Output is correct
17 Correct 824 ms 59952 KB Output is correct
18 Correct 852 ms 60928 KB Output is correct
19 Correct 343 ms 74468 KB Output is correct
20 Correct 341 ms 74488 KB Output is correct
21 Correct 366 ms 74448 KB Output is correct
22 Correct 358 ms 74336 KB Output is correct

Subtask #6
0 / 22.0

# 결과 실행 시간 메모리 Grader output
1 Correct 914 ms 62936 KB Output is correct
2 Correct 347 ms 73976 KB Output is correct
3 Correct 438 ms 45304 KB Output is correct
4 Correct 427 ms 45048 KB Output is correct
5 Correct 430 ms 45236 KB Output is correct
6 Correct 462 ms 45176 KB Output is correct
7 Correct 509 ms 45176 KB Output is correct
8 Correct 444 ms 45304 KB Output is correct
9 Correct 419 ms 45048 KB Output is correct
10 Correct 429 ms 45304 KB Output is correct
11 Correct 457 ms 45176 KB Output is correct
12 Correct 859 ms 62200 KB Output is correct
13 Correct 419 ms 45176 KB Output is correct
14 Correct 263 ms 68472 KB Output is correct
15 Correct 247 ms 65272 KB Output is correct
16 Correct 829 ms 60992 KB Output is correct
17 Correct 824 ms 59952 KB Output is correct
18 Correct 852 ms 60928 KB Output is correct
19 Correct 343 ms 74468 KB Output is correct
20 Correct 341 ms 74488 KB Output is correct
21 Correct 366 ms 74448 KB Output is correct
22 Correct 358 ms 74336 KB Output is correct
23 Correct 885 ms 62276 KB Output is correct
24 Correct 317 ms 52856 KB Output is correct
25 Correct 453 ms 44152 KB Output is correct
26 Correct 461 ms 44280 KB Output is correct
27 Correct 461 ms 44280 KB Output is correct
28 Correct 447 ms 40952 KB Output is correct
29 Correct 464 ms 41080 KB Output is correct
30 Correct 448 ms 40952 KB Output is correct
31 Correct 468 ms 41208 KB Output is correct
32 Correct 455 ms 41208 KB Output is correct
33 Correct 458 ms 41084 KB Output is correct
34 Correct 768 ms 57976 KB Output is correct
35 Correct 541 ms 41244 KB Output is correct
36 Correct 237 ms 58032 KB Output is correct
37 Correct 209 ms 38720 KB Output is correct
38 Incorrect 790 ms 58772 KB Output isn't correct
39 Halted 0 ms 0 KB -

Subtask #7
0 / 27.0

# 결과 실행 시간 메모리 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 12 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 10 ms 14592 KB Output is correct
8 Correct 9 ms 14592 KB Output is correct
9 Correct 12 ms 14972 KB Output is correct
10 Correct 11 ms 14848 KB Output is correct
11 Correct 11 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 11 ms 14720 KB Output is correct
16 Correct 11 ms 14720 KB Output is correct
17 Correct 1234 ms 79128 KB Output is correct
18 Correct 1202 ms 79644 KB Output is correct
19 Correct 1286 ms 78668 KB Output is correct
20 Correct 1297 ms 78968 KB Output is correct
21 Correct 1387 ms 78892 KB Output is correct
22 Correct 1493 ms 80332 KB Output is correct
23 Correct 1405 ms 79992 KB Output is correct
24 Correct 1253 ms 80376 KB Output is correct
25 Correct 1346 ms 80304 KB Output is correct
26 Correct 1520 ms 79408 KB Output is correct
27 Correct 1407 ms 79284 KB Output is correct
28 Correct 1175 ms 80400 KB Output is correct
29 Correct 1240 ms 79224 KB Output is correct
30 Correct 1181 ms 79480 KB Output is correct
31 Correct 1484 ms 79424 KB Output is correct
32 Correct 1450 ms 79736 KB Output is correct
33 Correct 914 ms 62936 KB Output is correct
34 Correct 347 ms 73976 KB Output is correct
35 Correct 438 ms 45304 KB Output is correct
36 Correct 427 ms 45048 KB Output is correct
37 Correct 430 ms 45236 KB Output is correct
38 Correct 462 ms 45176 KB Output is correct
39 Correct 509 ms 45176 KB Output is correct
40 Correct 444 ms 45304 KB Output is correct
41 Correct 419 ms 45048 KB Output is correct
42 Correct 429 ms 45304 KB Output is correct
43 Correct 457 ms 45176 KB Output is correct
44 Correct 859 ms 62200 KB Output is correct
45 Correct 419 ms 45176 KB Output is correct
46 Correct 263 ms 68472 KB Output is correct
47 Correct 247 ms 65272 KB Output is correct
48 Correct 829 ms 60992 KB Output is correct
49 Correct 824 ms 59952 KB Output is correct
50 Correct 852 ms 60928 KB Output is correct
51 Correct 343 ms 74468 KB Output is correct
52 Correct 341 ms 74488 KB Output is correct
53 Correct 366 ms 74448 KB Output is correct
54 Correct 358 ms 74336 KB Output is correct
55 Correct 885 ms 62276 KB Output is correct
56 Correct 317 ms 52856 KB Output is correct
57 Correct 453 ms 44152 KB Output is correct
58 Correct 461 ms 44280 KB Output is correct
59 Correct 461 ms 44280 KB Output is correct
60 Correct 447 ms 40952 KB Output is correct
61 Correct 464 ms 41080 KB Output is correct
62 Correct 448 ms 40952 KB Output is correct
63 Correct 468 ms 41208 KB Output is correct
64 Correct 455 ms 41208 KB Output is correct
65 Correct 458 ms 41084 KB Output is correct
66 Correct 768 ms 57976 KB Output is correct
67 Correct 541 ms 41244 KB Output is correct
68 Correct 237 ms 58032 KB Output is correct
69 Correct 209 ms 38720 KB Output is correct
70 Incorrect 790 ms 58772 KB Output isn't correct
71 Halted 0 ms 0 KB -