oj.uz

Submission #115212

# Submission time Handle Problem Language Result Execution time Memory
115212 2019-06-06T04:32:55 Z IOrtroiii One-Way Streets (CEOI17_oneway) C++14
100 / 100
 170 ms 22340 KB 
#include <bits/stdc++.h>

using namespace std;

const int N = 100100;

int n, m, q;
bool visit[N];
int p[N], ans[N];
vector<pair<int, int>> g[N];
vector<pair<int, int>> g2[N];
int num[N], low[N], tt;
int par[N], parid[N], dep[N];
vector<tuple<int, int, int>> tr;

int getp(int u) {
   if (p[u] == u) {
      return u;
   } else {
      return p[u] = getp(p[u]);
   }
}

void mrg(int u, int v) {
   p[getp(v)] = getp(u);
}

void dfs(int u, int pid) {
   num[u] = low[u] = ++tt;
   for (auto e : g[u]) {
      int v, id; tie(v, id) = e;
      if (id + pid) {
         if (num[v]) low[u] = min(low[u], num[v]);
         else {
            dfs(v, id);
            low[u] = min(low[u], low[v]);
            if (low[v] > num[u]) {
               tr.emplace_back(u, v, id);
            } else mrg(u, v);
         }
      }
   }
}

void dfs2(int u, int p) {
   visit[u] = true;
   for (auto e : g2[u]) {
      int v, id; tie(v, id) = e;
      if (v ^ p) {
         par[v] = u;
         parid[v] = -id;
         dep[v] = dep[u] + 1;
         dfs2(v, u);
      }
   }
}

int main() {
   scanf("%d %d", &n, &m);
   for (int i = 1; i <= n; ++i) p[i] = i;
   for (int i = 1; i <= m; ++i) {
      int u, v;
      scanf("%d %d", &u, &v);
      g[u].emplace_back(v, i);
      g[v].emplace_back(u, -i);
   }
   for (int i = 1; i <= n; ++i) {
      if (!num[i]) dfs(i, 0);
   }
   for (auto e : tr) {
      int u, v, id; tie(u, v, id) = e;
      u = getp(u), v = getp(v);
      g2[u].emplace_back(v, id);
      g2[v].emplace_back(u, -id);
   }
   for (int i = 1; i <= n; ++i) {
      if (p[i] == i && !visit[i]) dfs2(i, 0);
   }
   scanf("%d", &q);
   while (q--) {
      int u, v;
      scanf("%d %d", &u, &v);
      u = getp(u), v = getp(v);
      while (u ^ v) {
         if (dep[u] > dep[v]) {
            if (parid[u] > 0) ans[parid[u]] = 1;
            else ans[-parid[u]] = 2;
            mrg(par[u], u);
            u = getp(u);
         } else {
            if (parid[v] > 0) ans[parid[v]] = 2;
            else ans[-parid[v]] = 1;
            mrg(par[v], v);
            v = getp(v);
         }
      }
   }
   for (int i = 1; i <= m; ++i) {
      if (ans[i] == 0) putchar('B');
      else if (ans[i] == 1) putchar('R');
      else putchar('L');
   }
}

Compilation message

oneway.cpp: In function 'int main()':
oneway.cpp:59:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d %d", &n, &m);
    ~~~~~^~~~~~~~~~~~~~~~~
oneway.cpp:63:12: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
       scanf("%d %d", &u, &v);
       ~~~~~^~~~~~~~~~~~~~~~~
oneway.cpp:79:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d", &q);
    ~~~~~^~~~~~~~~~
oneway.cpp:82:12: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
       scanf("%d %d", &u, &v);
       ~~~~~^~~~~~~~~~~~~~~~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 5120 KB Output is correct
2 Correct 6 ms 5120 KB Output is correct
3 Correct 6 ms 5120 KB Output is correct
4 Correct 6 ms 5120 KB Output is correct
5 Correct 6 ms 5248 KB Output is correct
6 Correct 6 ms 5120 KB Output is correct
7 Correct 6 ms 5120 KB Output is correct
8 Correct 6 ms 5248 KB Output is correct
9 Correct 6 ms 5120 KB Output is correct
10 Correct 6 ms 5120 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 5120 KB Output is correct
2 Correct 6 ms 5120 KB Output is correct
3 Correct 6 ms 5120 KB Output is correct
4 Correct 6 ms 5120 KB Output is correct
5 Correct 6 ms 5248 KB Output is correct
6 Correct 6 ms 5120 KB Output is correct
7 Correct 6 ms 5120 KB Output is correct
8 Correct 6 ms 5248 KB Output is correct
9 Correct 6 ms 5120 KB Output is correct
10 Correct 6 ms 5120 KB Output is correct
11 Correct 57 ms 10160 KB Output is correct
12 Correct 62 ms 11384 KB Output is correct
13 Correct 75 ms 12792 KB Output is correct
14 Correct 103 ms 14736 KB Output is correct
15 Correct 107 ms 15220 KB Output is correct
16 Correct 112 ms 17516 KB Output is correct
17 Correct 109 ms 18792 KB Output is correct
18 Correct 102 ms 17772 KB Output is correct
19 Correct 114 ms 19692 KB Output is correct
20 Correct 55 ms 10748 KB Output is correct
21 Correct 53 ms 11512 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 5120 KB Output is correct
2 Correct 6 ms 5120 KB Output is correct
3 Correct 6 ms 5120 KB Output is correct
4 Correct 6 ms 5120 KB Output is correct
5 Correct 6 ms 5248 KB Output is correct
6 Correct 6 ms 5120 KB Output is correct
7 Correct 6 ms 5120 KB Output is correct
8 Correct 6 ms 5248 KB Output is correct
9 Correct 6 ms 5120 KB Output is correct
10 Correct 6 ms 5120 KB Output is correct
11 Correct 57 ms 10160 KB Output is correct
12 Correct 62 ms 11384 KB Output is correct
13 Correct 75 ms 12792 KB Output is correct
14 Correct 103 ms 14736 KB Output is correct
15 Correct 107 ms 15220 KB Output is correct
16 Correct 112 ms 17516 KB Output is correct
17 Correct 109 ms 18792 KB Output is correct
18 Correct 102 ms 17772 KB Output is correct
19 Correct 114 ms 19692 KB Output is correct
20 Correct 55 ms 10748 KB Output is correct
21 Correct 53 ms 11512 KB Output is correct
22 Correct 149 ms 20028 KB Output is correct
23 Correct 170 ms 18668 KB Output is correct
24 Correct 162 ms 18924 KB Output is correct
25 Correct 169 ms 22340 KB Output is correct
26 Correct 137 ms 19688 KB Output is correct
27 Correct 147 ms 18800 KB Output is correct
28 Correct 49 ms 8192 KB Output is correct
29 Correct 83 ms 11640 KB Output is correct
30 Correct 87 ms 12408 KB Output is correct
31 Correct 87 ms 11844 KB Output is correct
32 Correct 100 ms 15860 KB Output is correct