Submission #807716

#TimeUsernameProblemLanguageResultExecution timeMemory
807716dong_liuGroup Photo (JOI21_ho_t3)C++17
100 / 100
309 ms98324 KiB
#include <iostream> using namespace std; const int N = 5e3; int main() { int n; scanf("%d", &n); static int o[N + 1]; for (int i = 1; i <= n; i++) { int a; scanf("%d", &a); o[a] = i; } static int s[N + 1][N + 1]; for (int i = 1; i <= n; i++) for (int j = 1; j <= n; j++) s[i][j] = s[i - 1][j] + s[i][j - 1] - s[i - 1][j - 1] + (i < j && o[i] > o[j]); auto inv = [&](int i1, int i2, int j1, int j2) { return s[i2][j2] - s[i1 - 1][j2] - s[i2][j1 - 1] + s[i1 - 1][j1 - 1]; }; auto ninv = [&](int i, int j) { return (j - i + 1) * (j - i) / 2 - inv(i, j, i, j); }; static int f[N + 1]; for (int i = 1; i <= n; i++) { f[i] = ninv(1, i); for (int j = 1; j < i; j++) f[i] = min(f[i], f[j] + inv(1, j, j + 1, i) + ninv(j + 1, i)); } printf("%d\n", f[n]); return 0; }

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:8:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
    8 |   scanf("%d", &n);
      |   ~~~~~^~~~~~~~~~
Main.cpp:12:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   12 |     scanf("%d", &a);
      |     ~~~~~^~~~~~~~~~
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...