oj.uz

Submission #396600

# Submission time Handle Problem Language Result Execution time Memory
396600 2021-04-30T11:52:52 Z usachevd0 Ancient Books (IOI17_books) C++14
50 / 100
 736 ms 150044 KB 
#include <bits/stdc++.h>
#ifndef DEBUG
  #include "books.h"
#endif

using namespace std;

#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define all(a) (a).begin(), (a).end()
using ll = long long;
using ull = unsigned long long;
using pii = pair<int, int>;
using pil = pair<int, ll>;
using pli = pair<ll, int>;
using pll = pair<ll, ll>;
using ld = long double;
template<typename T1, typename T2> bool chkmin(T1 &x, T2 y) {
  return y < x ? (x = y, true) : false; 
}
template<typename T1, typename T2> bool chkmax(T1 &x, T2 y) {
  return y > x ? (x = y, true) : false;
}
void debug_out() {
  cerr << endl;
}
template<typename T1, typename... T2> void debug_out(T1 A, T2... B) {
  cerr << ' ' << A;
  debug_out(B...);
}
template<typename T> void mdebug_out(T* a, int n) {
  for (int i = 0; i < n; ++i) {
    cerr << a[i] << ' ';
  }
  cerr << endl;
}
#ifdef DEBUG
  #define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
  #define mdebug(a, n) cerr << #a << ": ", mdebug_out(a, n)
#else
  #define debug(...) 1337
  #define mdebug(a, n) 1337
#endif
template<typename T> ostream& operator << (ostream& stream, const vector<T> &v) {
  for (auto& x : v) {
    stream << x << ' ';
  }
  return stream;
}
template<typename T1, typename T2> ostream& operator << (ostream& stream, const pair<T1, T2>& p) {
  return stream << p.first << ' ' << p.second;
}


const int INF32 = 1e9;

ll minimum_walk(vector<int> p, int s) {
  int n = p.size();
  vector<int> p_inv(n);
  for (int i = 0; i < n; ++i) {
    p_inv[p[i]] = i;
  }

  ll Ans = 0;
  for (int i = 0; i < n; ++i) Ans += labs(p[i] - i);

  vector<int> cyc(n, -1);
  vector<int> cl(n, +INF32), cr(n, -INF32);
  int C = 0;
  for (int i = 0; i < n; ++i) {
    if (p[i] != i && cyc[i] == -1) {
      int c = C++;
      cl[c] = cr[c] = i;
      int x = i;
      do {
        cyc[x] = c;
        chkmax(cr[c], x);
        x = p[x];
      } while (x != i);
    }
  }
  if (!C) return 0;

  vector<int> G[C];
  vector<int> GR[C];
  for (int c = 0; c < C; ++c) {
    for (int i = cl[c]; i <= cr[c]; ++i) {
      if (cyc[i] != -1 && cyc[i] != c) {
        G[c].push_back(cyc[i]);
        GR[cyc[i]].push_back(c);
      }
    }
  }

  vector<char> used(C, false);
  vector<int> ord;
  function<void(int)> dfs = [&](int v) {
    used[v] = true;
    for (int& u : G[v])
      if (!used[u])
        dfs(u);
    ord.push_back(v);
  };
  for (int c = 0; c < C; ++c)
    if (!used[c])
      dfs(c);
  reverse(all(ord));
  vector<int> scc(C, -1);
  int S = 0;
  function<void(int)> dfs1 = [&](int v) {
    scc[v] = S;
    for (int& u : GR[v])
      if (scc[u] == -1)
        dfs1(u);
  };
  for (int& v : ord) {
    if (scc[v] == -1) {
      dfs1(v);
      ++S;
    }
  }

  vector<char> src(S, true);
  for (int c = 0; c < C; ++c) {
    for (int d : G[c]) {
      if (scc[c] != scc[d]) {
        src[scc[d]] = false;
      }
    }
  }

  vector<int> sl(S, +INF32), sr(S, -INF32);
  for (int c = 0; c < C; ++c) {
    int s = scc[c];
    chkmin(sl[s], cl[c]);
    chkmax(sr[s], cr[c]);
  }
  vector<pii> segs;
  for (int s = 0; s < S; ++s) {
    if (src[s]) {
      segs.emplace_back(sl[s], sr[s]);
    }
  }
  sort(all(segs));
  for (int i = 0; i + 1 < segs.size(); ++i) {
    int r1 = segs[i].se;
    int l2 = segs[i + 1].fi;
    assert(r1 < l2);
    Ans += 2 * (l2 - r1);
  }
  bool inside = false;
  for (auto& g : segs) {
    if (g.fi <= s && s <= g.se) {
      inside = true;
      break;
    }
  }
  if (!inside) {
    if (s < segs[0].fi) {
      return Ans + 2 * labs(segs[0].fi - s);
    } else if (s > segs.back().se) {
      return Ans + 2 * labs(s - segs.back().se);
    } else {
      return Ans;
    }
  } else {
    int Add = INF32;
    {
      int l = s;
      while (cyc[l] == -1 || !src[scc[cyc[l]]]) --l;
      if (l == s) return Ans;
      /*vector<int> dp(n, 0);
      for (int j = s - 1; j > l; --j) {
        dp[j] = dp[j + 1];
        if (p[j] != j && j < p_inv[j] && p_inv[j] <= s) {
          chkmax(dp[j], p_inv[j] - j + dp[p_inv[j]]);
        }
      }
      vector<int> dq(n, 0);
      for (int j = l + 1; j <= s; ++j) {
        dq[j] = dq[j - 1];
        if (p[j] != j && l < p_inv[j] && p_inv[j] < j) {
          chkmax(dq[j], j - p_inv[j] + dq[p_inv[j]]);
        }
      }*/
      vector<int> cc(n, 0);
      /*for (int c = 0; c < C; ++c) {
        if (l < cl[c] && cl[c] <= s) {
          for (int i = cl[c]; i < min(cr[c], s); ++i) {
            cc[i] = 1;
          }
        }
      }*/
      for (int i = l + 1; i <= s; ++i) {
        if (1 || l < p[i] && p[i] <= s) {
          for (int j = max(l + 1, min(i, p[i])); j < min(max(i, p[i]), s); ++j) cc[j] = 1;
        }
      }
      chkmin(Add, 2 * (s - l) - 2 * accumulate(all(cc), 0));
    }
    {
      int r = s;
      while (cyc[r] == -1 || !src[scc[cyc[r]]]) ++r;
      if (r == s) throw;
      /*vector<int> dp(n, 0);
      for (int j = s + 1; j < r; ++j) {
        dp[j] = dp[j - 1];
        if (p[j] != j && s <= p_inv[j] && p_inv[j] < j) {
          chkmax(dp[j], j - p_inv[j] + dp[p_inv[j]]);
        }
      }
      debug(r - s, dp[r - 1]);*/
      vector<int> cc(n, 0);
      for (int c = 0; c < C; ++c) {
        if (s <= cr[c] && cr[c] < r) {
          for (int i = max(s, cl[c]); i < cr[c]; ++i) {
            cc[i] = 1;
          }
        }
      }
      //chkmin(Add, 2 * (r - s) - 2 * accumulate(all(cc), 0));
    }
    return Ans + Add;
  }

  /*
  if (s != 0) {
    bool inside = false;
    for (pii g : segs) {
      if (g.fi <= s && s <= g.se) {
        inside = true;
      }
    }
    return (ll)inside;
  }
  /**/
  return Ans;
}


#ifdef DEBUG
int32_t main() {
#ifdef DEBUG
  freopen("in", "r", stdin);
#endif
  ios::sync_with_stdio(0);
  cin.tie(0);

  int n, s;
  cin >> n >> s;
  vector<int> p(n);
  for (auto& x : p) cin >> x;
  cout << minimum_walk(p, s) << '\n';
    
  return 0;
}
#endif

Compilation message

books.cpp:238:3: warning: "/*" within comment [-Wcomment]
  238 |   /**/
      |    
books.cpp: In function 'll minimum_walk(std::vector<int>, int)':
books.cpp:147:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  147 |   for (int i = 0; i + 1 < segs.size(); ++i) {
      |                   ~~~~~~^~~~~~~~~~~~~
books.cpp:197:27: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
  197 |         if (1 || l < p[i] && p[i] <= s) {
      |                  ~~~~~~~~~^~~~~~~~~~~~

Subtask #1
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 328 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 1 ms 204 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 1 ms 204 KB Output is correct
6 Correct 1 ms 204 KB Output is correct
7 Correct 1 ms 204 KB Output is correct
8 Correct 1 ms 204 KB Output is correct
9 Correct 1 ms 204 KB Output is correct
10 Correct 1 ms 204 KB Output is correct
11 Correct 1 ms 204 KB Output is correct
12 Correct 1 ms 204 KB Output is correct
13 Correct 1 ms 204 KB Output is correct
14 Correct 1 ms 204 KB Output is correct
15 Correct 1 ms 204 KB Output is correct
16 Correct 1 ms 204 KB Output is correct
17 Correct 1 ms 204 KB Output is correct
18 Correct 1 ms 204 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 328 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 1 ms 204 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 1 ms 204 KB Output is correct
6 Correct 1 ms 204 KB Output is correct
7 Correct 1 ms 204 KB Output is correct
8 Correct 1 ms 204 KB Output is correct
9 Correct 1 ms 204 KB Output is correct
10 Correct 1 ms 204 KB Output is correct
11 Correct 1 ms 204 KB Output is correct
12 Correct 1 ms 204 KB Output is correct
13 Correct 1 ms 204 KB Output is correct
14 Correct 1 ms 204 KB Output is correct
15 Correct 1 ms 204 KB Output is correct
16 Correct 1 ms 204 KB Output is correct
17 Correct 1 ms 204 KB Output is correct
18 Correct 1 ms 204 KB Output is correct
19 Correct 1 ms 332 KB Output is correct
20 Correct 1 ms 332 KB Output is correct
21 Correct 1 ms 204 KB Output is correct
22 Correct 1 ms 204 KB Output is correct
23 Correct 1 ms 204 KB Output is correct
24 Correct 1 ms 332 KB Output is correct
25 Correct 1 ms 332 KB Output is correct
26 Correct 1 ms 332 KB Output is correct
27 Correct 1 ms 332 KB Output is correct
28 Correct 1 ms 332 KB Output is correct
29 Correct 1 ms 332 KB Output is correct

Subtask #3
28.0 / 28.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 328 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 1 ms 204 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 1 ms 204 KB Output is correct
6 Correct 1 ms 204 KB Output is correct
7 Correct 1 ms 204 KB Output is correct
8 Correct 1 ms 204 KB Output is correct
9 Correct 1 ms 204 KB Output is correct
10 Correct 1 ms 204 KB Output is correct
11 Correct 1 ms 204 KB Output is correct
12 Correct 1 ms 204 KB Output is correct
13 Correct 1 ms 204 KB Output is correct
14 Correct 1 ms 204 KB Output is correct
15 Correct 1 ms 204 KB Output is correct
16 Correct 1 ms 204 KB Output is correct
17 Correct 1 ms 204 KB Output is correct
18 Correct 1 ms 204 KB Output is correct
19 Correct 1 ms 332 KB Output is correct
20 Correct 1 ms 332 KB Output is correct
21 Correct 1 ms 204 KB Output is correct
22 Correct 1 ms 204 KB Output is correct
23 Correct 1 ms 204 KB Output is correct
24 Correct 1 ms 332 KB Output is correct
25 Correct 1 ms 332 KB Output is correct
26 Correct 1 ms 332 KB Output is correct
27 Correct 1 ms 332 KB Output is correct
28 Correct 1 ms 332 KB Output is correct
29 Correct 1 ms 332 KB Output is correct
30 Correct 343 ms 72452 KB Output is correct
31 Correct 419 ms 104356 KB Output is correct
32 Correct 180 ms 23668 KB Output is correct
33 Correct 182 ms 39788 KB Output is correct
34 Correct 185 ms 39872 KB Output is correct
35 Correct 208 ms 43372 KB Output is correct
36 Correct 256 ms 46404 KB Output is correct
37 Correct 259 ms 60588 KB Output is correct
38 Correct 273 ms 76224 KB Output is correct
39 Correct 278 ms 76556 KB Output is correct
40 Correct 314 ms 87768 KB Output is correct
41 Correct 354 ms 98012 KB Output is correct
42 Correct 385 ms 108764 KB Output is correct
43 Correct 736 ms 150044 KB Output is correct

Subtask #4
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 332 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 1 ms 332 KB Output is correct
6 Incorrect 1 ms 332 KB 3rd lines differ - on the 1st token, expected: '22140', found: '22130'
7 Halted 0 ms 0 KB -

Subtask #5
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 328 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 1 ms 204 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 1 ms 204 KB Output is correct
6 Correct 1 ms 204 KB Output is correct
7 Correct 1 ms 204 KB Output is correct
8 Correct 1 ms 204 KB Output is correct
9 Correct 1 ms 204 KB Output is correct
10 Correct 1 ms 204 KB Output is correct
11 Correct 1 ms 204 KB Output is correct
12 Correct 1 ms 204 KB Output is correct
13 Correct 1 ms 204 KB Output is correct
14 Correct 1 ms 204 KB Output is correct
15 Correct 1 ms 204 KB Output is correct
16 Correct 1 ms 204 KB Output is correct
17 Correct 1 ms 204 KB Output is correct
18 Correct 1 ms 204 KB Output is correct
19 Correct 1 ms 332 KB Output is correct
20 Correct 1 ms 332 KB Output is correct
21 Correct 1 ms 204 KB Output is correct
22 Correct 1 ms 204 KB Output is correct
23 Correct 1 ms 204 KB Output is correct
24 Correct 1 ms 332 KB Output is correct
25 Correct 1 ms 332 KB Output is correct
26 Correct 1 ms 332 KB Output is correct
27 Correct 1 ms 332 KB Output is correct
28 Correct 1 ms 332 KB Output is correct
29 Correct 1 ms 332 KB Output is correct
30 Correct 343 ms 72452 KB Output is correct
31 Correct 419 ms 104356 KB Output is correct
32 Correct 180 ms 23668 KB Output is correct
33 Correct 182 ms 39788 KB Output is correct
34 Correct 185 ms 39872 KB Output is correct
35 Correct 208 ms 43372 KB Output is correct
36 Correct 256 ms 46404 KB Output is correct
37 Correct 259 ms 60588 KB Output is correct
38 Correct 273 ms 76224 KB Output is correct
39 Correct 278 ms 76556 KB Output is correct
40 Correct 314 ms 87768 KB Output is correct
41 Correct 354 ms 98012 KB Output is correct
42 Correct 385 ms 108764 KB Output is correct
43 Correct 736 ms 150044 KB Output is correct
44 Correct 1 ms 332 KB Output is correct
45 Correct 1 ms 332 KB Output is correct
46 Correct 1 ms 332 KB Output is correct
47 Correct 1 ms 204 KB Output is correct
48 Correct 1 ms 332 KB Output is correct
49 Incorrect 1 ms 332 KB 3rd lines differ - on the 1st token, expected: '22140', found: '22130'
50 Halted 0 ms 0 KB -