| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 772736 | PAndaS | Fountain (eJOI20_fountain) | C++14 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include<iostream>
#include<vector>
#include<stack>
#define K 20
using namespace std;
vector<vector<long>> up, sum;
long f(long u, long x){
long res = 0;
for(long i = 0; x; i++)if(x & (1 << i)){
res += sum[u][i];
u = up[u][i];
x -= (1 << i);
if(u == -1) break;
}
return res;
}
long jump(int u, int x){
for(long i = 0; x; i++) if(x & (1 << i)){
u = up[u][i];
x -= (1 << i);
if(u == -1) break;
}
return u;
}
int main(){
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
long n, q; cin >> n >> q;
vector<long> c(n), d(n);
for(long i = 0; i < n; i++) cin >> d[i] >> c[i];
up.resize(n, vector<long>(K, -1));
stack<pair<long, long>> st;
st.push(pair<long, long>(LONG_MAX, -1));
for(long i = n -1; i + 1; i--){
while(st.top().first < d[i]){
st.pop();
}
up[i][0] = st.top().second;
st.push(pair<long, long>(d[i], i));
}
for(long i = 1; i < K; i++) for(long j = 0; j < n; j++)if(up[j][i - 1] + 1) up[j][i] = up[up[j][i - 1]][i - 1];
sum.resize(n, vector<long>(K, -1));
for(long i = 0; i < n; i++) sum[i][0] = c[i];
for(long i = 1; i < K; i++) for(long j = 0; j < n; j++){
sum[j][i] = sum[j][i - 1];
if(up[j][i - 1] >= 0) sum[j][i] += sum[up[j][i - 1]][i - 1];
}
long res, v;
long l, m, r;
for(long i = 0; i < q; i++){
cin >> res >> v;
res--;
l = 0;
r = n - 1;
while(l ^ r){
m = (l + r) / 2;
if(f(res, m) < v) l = m + 1;
else r = m;
}
cout << jump(res, l - 1) + 1 << '\n';
}
return 0;
}