Submission #966251

#	Time	Username	Problem	Language	Result	Execution time	Memory
966251		vjudge1	Alternating Heights (CCO22_day1problem1)	C++17	0 / 25	122 ms	3416 KiB

Main

#include<bits/stdc++.h>

using namespace std;

vector<int> vc[2020];
int n,k,q, arr[2020], dp[2020], vis[2020];

bool cycle(int u){
    vis[u] = 1;
    for(auto x:vc[u]) if(vis[x] || (!vis[x] && cycle(x))) return true;
    vis[u] = 2;
    return false;
}

int main(){
    cin.tie(nullptr)->sync_with_stdio(false);
    cin >> n >> k >> q;
    for(int i = 1; i<=n; ++i){
        cin >> arr[i];
        int l = 1, r = i;
        dp[i] = i;
        while(l <= r){
            int mid = (l + r) >> 1;
            bool check = true;
            memset(vis, 0, sizeof(vis));
            for(int j = 1; j<=k; ++j) vc[j].clear();
            for(int j = i; j>mid; --j){
                if(j&1) vc[arr[j]].emplace_back(arr[j - 1]);
                else vc[arr[j - 1]].emplace_back(arr[j]);
            }
            for(int j = i; j>mid && check; --j) if(!vis[j] && cycle(arr[j])) check = false;
            if(check){
                dp[i] = mid;
                r = mid - 1;
            }
            else l = mid+1;
        }
    }
    while(q--){
        int x, y; cin >> x >> y;
        dp[y] <= x ? cout << "YES\n" : cout << "NO\n";
    }
}

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