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| #include <iostream>
#include <vector>
#include <string>
#include <iomanip>
using namespace std;
struct State {
double v;
double c;
};
vector<State> history;
void init(double v, double c) {
history.push_back({v, c});
}
void push_solution(double v, double c) {
State cur = history.back();
double total_v = cur.v + v;
double total_c = (cur.v * cur.c + v * c) / total_v;
history.push_back({total_v, total_c});
}
void pop_solution() {
if (history.size() > 1) {
history.pop_back();
}
}
void print_current() {
State cur = history.back();
cout << (long long)cur.v << " " << fixed << setprecision(5) << cur.c << "\n";
}
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
double v0, c0;
int n;
if (cin >> v0 >> c0) {
init(v0, c0);
cin >> n;
while (n--) {
string op;
cin >> op;
if (op == "P") {
double v, c;
cin >> v >> c;
push_solution(v, c);
} else if (op == "Z") {
pop_solution();
}
print_current();
}
}
return 0;
}
|