Submission #696335

#	Time	Username	Problem	Language	Result	Execution time	Memory
696335		dongliu0426	Difference (POI11_roz)	C++17	90 / 100	620 ms	33672 KiB

roz

#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")

#include <iostream>
#include <vector>
using namespace std;

const int N = 1e6;

int main() {
  int n;
  scanf("%d", &n);
  static char s[N];
  scanf("%s", s);
  static vector<int> u[N];
  for (int i = 0; i < n; i++)
    u[s[i] - 'a'].push_back(i);
  int ans = 0;
  for (int i = 0; i < 26; i++)
    for (int j = 0; j < 26; j++) {
      if (i == j)
        continue;
      static int t[N + 1];
      int m = 0, l = 0, r = 0;
      while (l < (int) u[i].size() || r < (int) u[j].size())
        if (l == (int) u[i].size())
          t[++m] = -1, r++;
        else if (r == (int) u[j].size())
          t[++m] = +1, l++;
        else if (u[i][l] < u[j][r])
          t[++m] = +1, l++;
        else
          t[++m] = -1, r++;
      int p = 0, c = 0, d = 0, mn = n;
      for (int k = 1; k <= m; k++) {
        c += t[k];
        if (t[k] == -1) {
          for (int k_ = p; k_ < k; k_++)
            mn = min(mn, d += t[k_]);
          p = k;
        }
        ans = max(ans, c - mn);
      }
    }
  printf("%d\n", ans);
  return 0;
}

Compilation message (stderr)

roz.cpp: In function 'int main()':
roz.cpp:12:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   12 |   scanf("%d", &n);
      |   ~~~~~^~~~~~~~~~
roz.cpp:14:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   14 |   scanf("%s", s);
      |   ~~~~~^~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 0 / 10