Submission #5203

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Source Code Expand

#include <stdio.h>
#include <iostream>
#include <cmath>
using namespace std;

int N, start, goal;
double x, y;

double nextX(int step){
  int dy = N - y;
  int dx = x - goal;

  if (dy == 0) return -1;

  return (double)(dx * step) / (double)dy;
}


main(){

  cin >> N >> start >> goal;

  double d = 0;

  x = start;
  y = 0;
  //cout << "x: " << x << ", y: " << y << endl;

  for (int i = 0; i <= N; i++){
    int c1, c2;
    cin >> c1 >> c2;

    double next = x + nextX(i - y);
    //cout << "next:" << c1 << " / " << next << " / " << c2 << endl;

    if (c1 <= next && next <= c2){
    }else{
      //int nx = min(abs(x-c1), abs(x-c2));
      int nx = abs(x-c1) < abs(x-c2) ? c1 : c2;
      d += sqrt((double)((nx - x) * (nx - x) + (i - y) * (i - y)));
      x = nx;
      y = i;
      //cout << "#" << i << ",x: " << x << ", y: " << y << ", d: " << d << endl;
    }
  }
  d += sqrt((double)((goal - x) * (goal - x) + (N - y) * (N - y)));
  printf("%.14g\n", d);
}

Submission Info

Judge Result