Submission #26052124

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Source Code Expand

#include <algorithm>
#include <iostream>
#include <vector>

template <class T> std::vector<int> shrink_coordinate(std::vector<T> &a) {
  std::vector<T> b = a;

  std::sort(b.begin(), b.end());
  b.erase(std::unique(b.begin(), b.end()), b.end());

  int N = a.size();

  std::vector<int> res(N);
  for (int i = 0; i < N; i++) {
    res[i] = std::lower_bound(b.begin(), b.end(), a[i]) - b.begin();
  }

  return res;
}

int main() {
  int N, C;
  std::cin >> N >> C;

  std::vector<int> a(N), b(N), c(N);
  std::vector<int> x(2 * N);
  for (int i = 0; i < N; i++) {
    std::cin >> a[i] >> b[i] >> c[i];
    x[i] = a[i];
    x[i + N] = b[i] + 1;
  }

  std::vector<int> shrink_x = shrink_coordinate(x);

  std::vector<long long> prefix_sum(2 * N + 1, 0);
  for (int i = 0; i < N; i++) {
    prefix_sum[shrink_x[i]] += c[i];
    prefix_sum[shrink_x[i + N]] -= c[i];
  }

  for (int i = 1; i <= 2 * N; i++) {
    prefix_sum[i] += prefix_sum[i - 1];
  }

  std::sort(x.begin(), x.end());
  x.erase(unique(x.begin(), x.end()), x.end());

  const int M = x.size();

  long long ans = 0;
  for (int i = 0; i < M - 1; i++) {
    long long cost = std::min(prefix_sum[i], (long long)C);
    long long days = x[i + 1] - x[i];

    ans += cost * days;
  }

  std::cout << ans << "\n";

  return 0;
}

Submission Info

Judge Result