제출 #1124837

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1124837		VinhLuu	Alternating Heights (CCO22_day1problem1)	C++20	10 / 25	1070 ms	27984 KiB

Main

#include <bits/stdc++.h>
//#define int long long
#define ll long long
#define all(lpv) lpv.begin(), lpv.end()
#define fi first
#define se second
#define pot(x, y) lower_bound(x.begin(), x.end(), y) - x.begin()
using namespace std;

typedef pair<int,int> pii;

const int N = 1e6 + 5;
const int oo = 1e9;

int n, f[N], k, q, a[N], flag[N], deg[N], id[N];
vector<int> p[N];

int demin, in[N], en[N];

void dfs(int u) {
  in[u] = ++demin;
  for(auto j : p[u]) {
    if(!in[j]) {
      dfs(j);
    }
  }
  en[u] = demin;
}

bool kt(int u,int v) {
  return in[u] <= in[v] && in[v] <= en[u];
}

signed main() {
  ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
  #define task "v"
  if(fopen(task ".inp","r")) {
    freopen(task ".inp","r",stdin);
    freopen(task ".out","w",stdout);
  }
  cin >> n >> k >> q;
  for(int i = 1; i <= n; i ++) cin >> a[i];

  for(int i = 1; i <= n; i ++) {
    f[i] = i;
    int l = i + 1, r = n, mid;
//    if(i != 1) continue;
    while(l <= r) {
      mid = (l + r) / 2;
//      cerr << mid << " check\n";
      for(int j = 1; j <= k; j ++) {
        id[j] = j, flag[j] = 0, p[j].clear(), deg[j] = 0;
        in[j] = en[j] = 0;
      }
      demin = 0;
      for(int j = i; j < mid; j ++) {
        if(j % 2 == i % 2) { // >
          p[a[j]].push_back(a[j + 1]);
        } else {
          p[a[j + 1]].push_back(a[j]);
        }
      }
      for(int h = 1; h <= k; h ++) {
        int j = id[h];
        if(in[j]) continue;
        dfs(j);
      }
      bool ff = true;
      for(int j = 1; j <= k; j ++) {
        for(auto h : p[j]) {
          if(kt(h, j)) {
            ff = false;
            break;
          }
        }
        if(!ff) break;
      }

      if(ff) f[i] = mid, l = mid + 1;
      else r = mid - 1;
    }
  }

  while(q--) {
    int l, r; cin >> l >> r;
    if(f[l] < r) cout << "NO\n";
    else cout << "YES\n";
  }
}

컴파일 시 표준 에러 (stderr) 메시지

Main.cpp: In function 'int main()':
Main.cpp:38:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   38 |     freopen(task ".inp","r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:39:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   39 |     freopen(task ".out","w",stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

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