Submission #1166878

#	Time	Username	Problem	Language	Result	Execution time	Memory
1166878		SmuggingSpun	Birthday gift (IZhO18_treearray)	C++20	12 / 100	16 ms	328 KiB

treearray

#include<bits/stdc++.h>
#define taskname "C"
using namespace std;
int n, m, q;
namespace sub1{
    void solve(){
        vector<vector<int>>g(n + 1);
        for(int i = 1; i < n; i++){
            int u, v;
            cin >> u >> v;
            g[u].emplace_back(v);
            g[v].emplace_back(u);
        }
        vector<int>parent(n + 1), h(n + 1);
        function<void(int)>dfs;
        dfs = [&] (int s){
            for(int& d : g[s]){
                if(d != parent[s]){
                    h[d] = h[parent[d] = s] + 1;
                    dfs(d);
                }
            }
        };
        dfs(parent[1] = h[1] = 1);
        auto lca = [&] (int u, int v){
            while(u != v){
                if(h[u] < h[v]){
                    swap(u, v);
                }
                u = parent[u];
            }
            return u;
        };
        vector<int>a(m + 1);
        for(int i = 1; i <= m; i++){
            cin >> a[i];
        }
        for(int _ = 0; _ < q; _++){
            int _t;
            cin >> _t;
            if(_t == 1){
                int p;
                cin >> p >> a[p];
            }
            else{
                int l, r, v;
                cin >> l >> r >> v;
                int L = -1, R = -1;
                for(int i = l; i <= r && L == -1; i++){
                    int u = a[i];
                    for(int j = i; j <= r; j++){
                        if((u = lca(u, a[j])) == v){
                            L = i;
                            R = j;
                            break;
                        }
                    }
                }
                cout << L << " " << R << "\n";
            }
        }
    }
}
int main(){
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	if(fopen(taskname".inp", "r")){
		freopen(taskname".inp", "r", stdin);
	}
    cin >> n >> m >> q;
    if(max({n, m, q}) <= 100){
        sub1::solve();
    }
}

Compilation message (stderr)

treearray.cpp: In function 'int main()':
treearray.cpp:67:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   67 |                 freopen(taskname".inp", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 12 / 12
• Subtask 2: 0 / 18
• Subtask 3: 0 / 26
• Subtask 4: 0 / 44