Submission #696398

#	Time	Username	Problem	Language	Result	Execution time	Memory
696398		Cross_Ratio	Through Another Maze Darkly (CCO21_day1problem3)	C++14	4 / 25	680 ms	156072 KiB

Main

#include <bits/stdc++.h>
#define int long long
using namespace std;
vector<int> adj[800005];
int num[800005];
void dfs(int c, int p) {
    int i, j;
    if(p == -1) {
        int n = num[c];
        vector<int> V(adj[c].size());
        int sz = adj[c].size();
        for(i=0;i<sz;i++) {
            V[i] = adj[c][(i+n)%sz];
        }
        adj[c] = V;
        num[c] = (num[c] + sz - n) % sz;
    }
    else {
        int n = -1;
        int sz = adj[c].size();
        for(i=0;i<sz;i++) {
            if(adj[c][i]==p) n = i;
        }
        vector<int> V(sz);
        for(i=0;i<sz;i++) {
            V[i] = adj[c][(i+n)%sz];
        }
        adj[c] = V;
        num[c] = (num[c] + sz - n) % sz;
    }
    for(int n : adj[c]) {
        if(n ==p) continue;
        dfs(n, c);
    }
}
vector<array<int, 2>> Query;
int ans[800005];
signed main() {
    cin.sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int N, Q;
    cin >> N >> Q;
    int i, j;
    for(i=0;i<N;i++) {
        int k;
        cin >> k;
        for(j=0;j<k;j++) {
            int c;
            cin >> c;
            adj[i].push_back(c-1);
        }
        num[i] = 1 % k;
    }
    dfs(0, -1);
    vector<int> V1, V2;
    V1.push_back(0);
    for(i=1;i<N;i++) {
        if(num[i]==0) V1.push_back(2*i);
    }
    V2.resize(V1.size());
    int sz = V1.size();
    for(i=0;i<sz;i++) {
        V2[i] = (i ? V2[i-1] : 0) + V1[i];
    }
    /*for(i=0;i<sz;i++) cout << V1[i] << ' ';
    cout << '\n';
    for(i=0;i<sz;i++) cout << V2[i] << ' ';
    cout << '\n';*/
    for(i=0;i<Q;i++) {
        int a;
        cin >> a;
        if(a >= V2[sz-1]) {
            a = (a - V2[sz-1]) % (2*(N-1));
            if(a >= N-1) cout << 2*N-1 - a << '\n';
            else cout << a+1 << '\n';
            continue;
        }
        int c = upper_bound(V2.begin(),V2.end(),a) - V2.begin() - 1;
        a = (a - V2[c]) % V1[c+1];
        //cout << c << ' ' << V2[c] << ' ' << V1[c+1] << '\n';
        //cout << a << ' ';
        if(a > V1[c+1] / 2) cout << V1[c+1]+1 - a << '\n';
        else cout << a + 1 << '\n';

    }
    return 0;
    int ma = 0;
    for(i=0;i<Q;i++) {
        int a;
        cin >> a;
        if(a >= N*N) {
            a = (a - N*N) % (2*(N-1)) + N*N;
        }
        ma = max(ma, a);
        Query.push_back({a, i});
    }
    sort(Query.begin(),Query.end());
    int pt = 0, cnt = 0;
    int qt = 0;
    while(cnt <= ma) {
        cnt++;
        int p2 = adj[pt][num[pt]];
        num[pt] = (num[pt] + 1) % adj[pt].size();
        pt = p2;
        while(qt < Query.size() && Query[qt][0]==cnt) {
            ans[Query[qt][1]] = pt;
            qt++;
        }
    }
    for(i=0;i<Q;i++) cout << ans[i]+1 << '\n';
}

Compilation message (stderr)

Main.cpp: In function 'void dfs(long long int, long long int)':
Main.cpp:7:12: warning: unused variable 'j' [-Wunused-variable]
    7 |     int i, j;
      |            ^
Main.cpp: In function 'int main()':
Main.cpp:106:18: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::array<long long int, 2> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  106 |         while(qt < Query.size() && Query[qt][0]==cnt) {
      |               ~~~^~~~~~~~~~~~~~

• Subtask 1: 4 / 4
• Subtask 2: 0 / 4
• Subtask 3: 0 / 12
• Subtask 4: 0 / 5