USACO 2015 December Contest Bronze Division - Fence Painting

Problem link: here

Solution Author: Stefan Dascalescu

Problem Solution

This problem only requires simple casework where we need to consider interval intersections.

Source codes

The source codes in C++ and Python can be seen below.

#include <bits/stdc++.h>
using namespace std;

int main()
{
    ifstream cin("paint.in");
    ofstream cout("paint.out");

    int aL, aR, bL, bR;
    cin >> aL >> aR;
    cin >> bL >> bR;

    if(aL > bL)
        swap(aL, bL), swap(aR, bR);

    if(aR < bL)
        cout << aR - aL + bR - bL;
    else
        cout << max(aR, bR) - aL;
    return 0;
}

with open("paint.in", "r") as fin:
    aL, aR = map(int, fin.readline().split())
    bL, bR = map(int, fin.readline().split())

if aL > bL:
    aL, bL = bL, aL
    aR, bR = bR, aR

if aR < bL:
    ans = (aR - aL) + (bR - bL)
else:
    ans = max(aR, bR) - aL

with open("paint.out", "w") as fout:
    fout.write(str(ans))