Submission #370735

#	Time	Username	Problem	Language	Result	Execution time	Memory
370735		Traduttore	Fountain (eJOI20_fountain)	C++14	0 / 100	404 ms	81132 KiB

fountain

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ll long long
#define F first
#define S second
#define pb push_back
#define ld long double
#define int ll
#define pll pair <ll,ll>
#define IOS ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0)
#define TIME 1.0*clock()/CLOCKS_PER_SEC
using namespace std;
using namespace __gnu_pbds;
mt19937_64 gen(time(0));
int n,q;
vector <int> a;
vector <int> b;
void init() {
    cin>>n>>q;
    a.resize(n);
    b.resize(n);
    for (int i = 0;i < n;i++)
        cin>>a[i]>>b[i];
}
ll ans = 0;
void output() {
    cout<<ans<<'\n';
}
int up[(int)(1e6) ^ 1][(int)(20)];
int sum[(int)(1e6) ^ 1][(int)(20)];
struct sparse_table {
int sp[(int)(1e6) ^ 1][(int)(20)];
inline void build() {
for (int j = 0;j < 20;j++)
{
    for (int i = 0;i + (1<<j) <= n;i++)
        if (j == 0) sp[i][j] = a[i];
    else sp[i][j] = max(sp[i][j - 1],sp[i + (1<<(j - 1))][j - 1]);
}
}
inline int get (int l,int r)
{
    int LG = __lg(r - l + 1);
    return max(sp[l][LG],sp[r - (1<<LG) + 1][LG]);
}
};
sparse_table ST;
int used[(int)(1e6) ^ 1];
vector <int> gr[(int)(1e6) ^ 1];
inline void dfs (int v,int pr)
{
    up[v][0] = pr;
    sum[v][0] = b[v];
    for (int i = 1;i < 20;i++)
    if (up[v][i - 1] != -1) {
        up[v][i] = up[up[v][i - 1]][i - 1];
        sum[v][i] = sum[up[v][i - 1]][i - 1] + sum[v][i - 1];
    }
    for (auto to:gr[v])
    {
        if (to == pr) continue;
        dfs(to, v);
    }
}
void solve() {
    a[n] = 1e18;
    b[n] = 0;
    ++n;
    ST.build();
    for (int i = 0;i < n;i++)
    {
        for (int q = 0;q < 20;q++)
            up[i][q] = -1;
    }
    for (int i = 0;i < n;i++)
    {
        int left = i;
        int right = n - 1;
        int pos = -1;
        while (left <= right) {
            int mid = (left + right) >> 1;
            if (ST.get(i, mid) != a[i]) {
                pos = mid;
                right = mid - 1;
            }
            else left = mid + 1;
        }
        if (pos != -1) {
            gr[pos].pb(i);
            gr[i].pb(pos);
        }
    }
    dfs(n - 1,n - 1);
    while (q--)
    {
        int v,k;
        cin>>v>>k;
        --v;
        ans = -1;
        int suma = 0;
        for (int q = 0;q < 20;q++)
        {
            //cout<<v<<" "<<sum[v][q]<<" "<<k<<'\n';
            if (sum[v][q] >= k) {
                if (b[v] >= k) ans = v;
                else 
                ans = up[v][0];
                break;
            }
            else k-=sum[v][q];
            v = up[v][q];
            suma+=sum[v][q];
        }
        ++ans;
        output();
    }
}
int32_t main() {
    srand(time(0));
  //freopen("input.txt","r",stdin);
 // freopen("output.txt","w",stdout);
IOS;
int test;
test = 1;
while (test--) {
    init();
    solve();
}
exit(0);}
/*2 3 3 4*/

• Subtask 1: 0 / 30
• Subtask 2: 0 / 30
• Subtask 3: 0 / 40