oj.uz

Submission #261393

# Submission time Handle Problem Language Result Execution time Memory
261393 2020-08-11T17:04:23 Z Nightlight Aesthetic (NOI20_aesthetic) C++14
35 / 100
 2000 ms 72624 KB 
#include <cstdio>
#include <queue>
#include <cstring>
#define pii pair<long long, int>
using namespace std;
 
int N, M;
vector<pii> adj[300005];
priority_queue<pii, vector<pii>, greater<pii>> pq;
long long dist[2][300005];
int U[300005], V[300005];
bool can[300005], ada[300005];
long long W[300005], best[300005];
vector<pair<int, int>> adj2[300005];
int disc[300005], low[300005], waktu, need;
long long p1[300005], p2[300005], pp1[300005], pp2[300005];
bool ok;
 
void BFS(int id, int st) {
  memset(ada, 0, sizeof(ada));
  pq.emplace(0LL, st);
  dist[id][st] = 0;
  int u, v;
  long long len, w;
  while(!pq.empty()) {
    u = pq.top().second;
    len = pq.top().first;
    pq.pop();
    if(len != dist[id][u]) continue;
    for(pii now : adj[u]) {
      v = now.second;
      w = now.first;
      if(dist[id][v] > len + w) {
        dist[id][v] = len + w;
        pq.emplace(dist[id][v], v);
      }
    }
  }
}
 
void DFS(int u, int p) {
  disc[u] = low[u] = ++waktu;
  int v, id;
  for(pair<int, int> now : adj2[u]) {
    id = now.second;
    if(ada[id] == 0) continue;
    v = now.first; 
    if(disc[v] <= need) {
      DFS(v, u);
      if(low[v] > disc[u] && can[id] && disc[N] >= disc[v] && disc[N] <= waktu) {
        ok = 1;
      }else if(low[u] > low[v]) low[u] = low[v];
    }else if(p != v && low[u] > disc[v]) {
      low[u] = disc[v];
    }
  }
}
 
bool check(long long now) {
  ok = 0;
  need = waktu;
  for(int i = 1; i <= M; i++) {
    if(p1[i] > now && p2[i] > now) ada[i] = 0;
    else ada[i] = 1;
    if(pp1[i] > now && pp2[i] > now) can[i] = 1;
    else can[i] = 0;
  }
  DFS(1, 0);
  if(disc[N] <= need) return 1;
  if(ok) return 1;
  return 0;
}
 
int main() {
  memset(dist, 0x3f3f3f3f, sizeof(dist));
  scanf("%d %d", &N, &M);
  int u, v;
  long long w;
  for(int i = 1; i <= M; i++) {
    scanf("%d %d %lld", &u, &v, &w);
    U[i] = u, V[i] = v, W[i] = w;
    adj[u].emplace_back(w, v);
    adj[v].emplace_back(w, u);
    adj2[u].emplace_back(v, i);
    adj2[v].emplace_back(u, i);
  }
  for(int i = M - 1; i > 0; i--) {
    best[i] = max(best[i + 1], W[i + 1]);
  }
  BFS(0, 1);
  BFS(1, N);
  for(int i = 1; i <= M; i++) {
    p1[i] = dist[0][U[i]] + W[i] + dist[1][V[i]];
    p2[i] = dist[0][V[i]] + W[i] + dist[1][U[i]];
    pp1[i] = dist[0][U[i]] + best[i] + W[i] + dist[1][V[i]];
    pp2[i] = dist[0][V[i]] + best[i] + W[i] + dist[1][U[i]];
  }
  long long l = dist[0][N], r = dist[0][N] + 1000000000, res = dist[0][N], mid;
  while(l <= r) {
    mid = (l + r) >> 1;
    if(check(mid)) {
      l = mid + 1;
      res = l;
    }else r = mid - 1;
  }
  printf("%lld\n", res);
}

Compilation message

Aesthetic.cpp: In function 'int main()':
Aesthetic.cpp:76:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d", &N, &M);
   ~~~~~^~~~~~~~~~~~~~~~~
Aesthetic.cpp:80:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d %lld", &u, &v, &w);
     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 19456 KB Output is correct
2 Correct 20 ms 19456 KB Output is correct
3 Correct 14 ms 19456 KB Output is correct
4 Correct 14 ms 19456 KB Output is correct
5 Correct 20 ms 19456 KB Output is correct
6 Correct 14 ms 19456 KB Output is correct
7 Correct 14 ms 19456 KB Output is correct
8 Correct 14 ms 19456 KB Output is correct

Subtask #2
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 19456 KB Output is correct
2 Correct 20 ms 19456 KB Output is correct
3 Correct 14 ms 19456 KB Output is correct
4 Correct 14 ms 19456 KB Output is correct
5 Correct 20 ms 19456 KB Output is correct
6 Correct 14 ms 19456 KB Output is correct
7 Correct 14 ms 19456 KB Output is correct
8 Correct 14 ms 19456 KB Output is correct
9 Correct 19 ms 19840 KB Output is correct
10 Correct 19 ms 19840 KB Output is correct
11 Correct 17 ms 19712 KB Output is correct
12 Correct 17 ms 19712 KB Output is correct
13 Correct 16 ms 19840 KB Output is correct
14 Correct 16 ms 19840 KB Output is correct
15 Correct 16 ms 19840 KB Output is correct
16 Correct 16 ms 19840 KB Output is correct

Subtask #3
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 922 ms 65664 KB Output is correct
2 Correct 855 ms 65800 KB Output is correct
3 Correct 846 ms 65512 KB Output is correct
4 Correct 874 ms 65400 KB Output is correct
5 Correct 904 ms 65816 KB Output is correct
6 Correct 932 ms 66552 KB Output is correct
7 Correct 894 ms 66336 KB Output is correct
8 Correct 902 ms 66680 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1006 ms 66440 KB Output is correct
2 Correct 939 ms 65936 KB Output is correct
3 Correct 874 ms 65144 KB Output is correct
4 Correct 870 ms 65144 KB Output is correct
5 Correct 908 ms 65608 KB Output is correct
6 Correct 882 ms 65844 KB Output is correct
7 Correct 941 ms 66008 KB Output is correct
8 Correct 892 ms 66168 KB Output is correct

Subtask #5
0 / 16.0

# Verdict Execution time Memory Grader output
1 Execution timed out 2091 ms 72624 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #6
0 / 22.0

# Verdict Execution time Memory Grader output
1 Execution timed out 2091 ms 72624 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #7
0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 19456 KB Output is correct
2 Correct 20 ms 19456 KB Output is correct
3 Correct 14 ms 19456 KB Output is correct
4 Correct 14 ms 19456 KB Output is correct
5 Correct 20 ms 19456 KB Output is correct
6 Correct 14 ms 19456 KB Output is correct
7 Correct 14 ms 19456 KB Output is correct
8 Correct 14 ms 19456 KB Output is correct
9 Correct 19 ms 19840 KB Output is correct
10 Correct 19 ms 19840 KB Output is correct
11 Correct 17 ms 19712 KB Output is correct
12 Correct 17 ms 19712 KB Output is correct
13 Correct 16 ms 19840 KB Output is correct
14 Correct 16 ms 19840 KB Output is correct
15 Correct 16 ms 19840 KB Output is correct
16 Correct 16 ms 19840 KB Output is correct
17 Correct 922 ms 65664 KB Output is correct
18 Correct 855 ms 65800 KB Output is correct
19 Correct 846 ms 65512 KB Output is correct
20 Correct 874 ms 65400 KB Output is correct
21 Correct 904 ms 65816 KB Output is correct
22 Correct 932 ms 66552 KB Output is correct
23 Correct 894 ms 66336 KB Output is correct
24 Correct 902 ms 66680 KB Output is correct
25 Correct 1006 ms 66440 KB Output is correct
26 Correct 939 ms 65936 KB Output is correct
27 Correct 874 ms 65144 KB Output is correct
28 Correct 870 ms 65144 KB Output is correct
29 Correct 908 ms 65608 KB Output is correct
30 Correct 882 ms 65844 KB Output is correct
31 Correct 941 ms 66008 KB Output is correct
32 Correct 892 ms 66168 KB Output is correct
33 Execution timed out 2091 ms 72624 KB Time limit exceeded
34 Halted 0 ms 0 KB -