Submission #1607745

---

Source Code Expand

#include <bits/stdc++.h>

using namespace std;

int main(void) {
  int n;
  cin >> n;

  int s, g;
  cin >> s >> g;

  vector<int> l(n + 1), r(n + 1);
  for (int i = 0; i <= n; i++) {
    cin >> l[i] >> r[i];
  }

  int pos = s, cnt = 1;
  double ans = 0.0;
  for (int i = 1; i < n; i++) {
    if (l[i] <= pos && pos <= r[i]) {
      cnt++;
    } else if (pos < l[i]) {
      ans += hypot(l[i] - pos, cnt);
      pos = l[i];
      cnt = 1;
    } else if (pos > r[i]) {      
      ans += hypot(pos - r[i], cnt);
      pos = r[i];
      cnt = 1;
    }
  }
  ans += hypot(g - pos, cnt);

  printf("%.12f\n", ans);

  return 0;
}

Submission Info

Judge Result