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OI-codes/S2OJ/790/790.cpp

77 lines
1.9 KiB
C++

#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
using namespace std;
struct node {
int t;
long long p;
node() {}
node(int _t, long long _p)
: t(_t), p(_p) {}
};
int n, t;
long long d, p, ans, bat, res[500005], tmp;
set<pair<long long, int>> s;
int main() {
std::ios::sync_with_stdio(false);
cin >> n >> t;
for (int i = 1; i <= n; i++) {
bat -= d;
while (d > 0) {
while (!s.empty() && !res[s.begin()->second]) {
s.erase(s.begin());
}
tmp = min(d, res[s.begin()->second]);
d -= tmp;
res[s.begin()->second] -= tmp;
while (!s.empty() && res[s.begin()->second] == 0) {
s.erase(s.begin());
}
}
cin >> d >> p;
if (d > t) {
cout << -1 << endl;
exit(0);
}
while (!s.empty() && p < s.rbegin()->first) {
ans -= res[s.rbegin()->second] * s.rbegin()->first;
ans += p * res[s.rbegin()->second];
res[i] += res[s.rbegin()->second];
res[s.rbegin()->second] = 0;
s.erase(--s.end());
s.insert(make_pair(p, i));
}
if (bat < t) {
tmp = t - bat;
ans += tmp * p;
res[i] += tmp;
s.insert(make_pair(p, i));
bat = t;
}
}
bat -= d;
while (d > 0) {
while (!s.empty() && (res[s.begin()->second] == 0)) {
s.erase(s.begin());
}
tmp = min(d, res[s.begin()->second]);
d -= tmp;
res[s.begin()->second] -= tmp;
while (!s.empty() && res[s.begin()->second] == 0) {
s.erase(s.begin());
}
}
while (!s.empty()) {
ans -= res[s.begin()->second] * s.begin()->first;
res[s.begin()->second] = 0;
s.erase(s.begin());
}
cout << ans << endl;
return 0;
}