#include<bits/stdc++.h>
#define sanastd using namespace std
sanastd;
const int MAXN = 1000 * 1000 + 10;
const long long INF = 1LL * 1000 * 1000 * 1000 * 1000 * 1000 * 1000 + 10;
int n, r[MAXN], x[MAXN];
long double ans[MAXN];
stack <int> balloon;
bool check(int ind1, int ind2, double mid)
{
long double d = (x[ind1] - x[ind2]) * (x[ind1] - x[ind2]) + (ans[ind2] - mid) * (ans[ind2] - mid);
if(sqrt(d) < mid + ans[ind2]) return 0;
else return 1;
}
int main ()
{
cout<<fixed<<setprecision(15);
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
cin >> n >> x[0] >> r[0];
balloon.push(0);
ans[0] = r[0];
cout << r[0] << endl;
for(int i = 1; i < n; i++){
cin >> x[i] >> r[i];
ans[i] = r[i];
while(!balloon.empty() and r[balloon.top()] <= ans[i]){
long double lo = 0, hi = ans[i] + 0.001;
while(hi - lo > 0.001){
long double mid = (hi + lo) / 2.0;
if(check(i, balloon.top(), mid)) lo = mid;
else hi = mid;
}
ans[i] = min(ans[i], lo);
if(ans[i] >= r[balloon.top()) balloon.pop();
}
if(!balloon.empty()){
long double lo = 0, hi = ans[i] + 0.001;
while(hi - lo > 0.001){
long double mid = (hi + lo) / 2.0;
if(check(i, balloon.top(), mid)) lo = mid;
else hi = mid;
}
ans[i] = min(ans[i], lo);
}
balloon.push(i);
cout << ans[i] << '\n';
}
return 0;
}
Compilation message
bal.cpp: In function 'int main()':
bal.cpp:38:41: error: expected ']' before ')' token
38 | if(ans[i] >= r[balloon.top()) balloon.pop();
| ^
| ]
