Submission #638576

#	Time	Username	Problem	Language	Result	Execution time	Memory
638576		morasha3	Alternating Heights (CCO22_day1problem1)	C++17	25 / 25	777 ms	13900 KiB

Main

#include <bits/stdc++.h>
using namespace std;
typedef int ll;
typedef   double ld;
const ll mod=1e9+7;
#define endl '\n'
bool dfs(vector<vector<int>>& v)
{
    int n = v.size();
    vector<int> deg(n);
    for (int a = 0; a < n; a++)
        for (int b : v[a])
            deg[b]++;

    vector<int> q;
    q.reserve(n);
    for (int i = 0; i < n; i++)
        if (deg[i] == 0)
            q.push_back(i);
    for (int rep = 0; rep < q.size(); rep++)
    {
        int c = q[rep];
        for (auto nxt : v[c])
        {
            deg[nxt]--;
            if (deg[nxt] == 0)
                q.push_back(nxt);
        }
    }
    return n>q.size();
}


int32_t main()
{
    //freopen("jumping.in","r",stdin);
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    ll n,k,q;
    cin>>n>>k>>q;
    ll arr[n];
    for(int i=0; i<n; i++)
        {cin>>arr[i]; arr[i]--;}
  vector<int> can(n);
    for (int rep : {0, 1}) {
        for (int l = rep, r = l; l < n; l += 2) {
            while (r < n) {
                vector<vector<int>> adj(k);
                for (int i = l; i < r; i++) {
                    if (i % 2 == l % 2) adj[arr[i]].push_back(arr[i + 1]);
                    else adj[arr[i + 1]].push_back(arr[i]);
                }
                if (dfs(adj)) break;
                r++;
            }
            can[l] = r;
        }
    }
    while (q--) {
        int l, r; cin >> l >> r, --l, --r;
        if (can[l] <= r) {
            cout << "NO\n";
        } else {
            cout << "YES\n";
        }
    }


    return 0;

}

Compilation message (stderr)

Main.cpp: In function 'bool dfs(std::vector<std::vector<int> >&)':
Main.cpp:20:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   20 |     for (int rep = 0; rep < q.size(); rep++)
      |                       ~~~~^~~~~~~~~~
Main.cpp:30:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   30 |     return n>q.size();
      |            ~^~~~~~~~~

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