val p03 = fun() {

    val claims = input_3.lines().map { line ->
        line.split("#", "@", ",", ":", "x")
            .filter { it.isNotEmpty() }
            .map { it.trim().toInt() }.let {
                Claim(it[0], it[1] + 1, it[2] + 1, it[3], it[4])
            }
    }.asSequence()

    val common = mutableSetOf<Pair<Int, Int>>()
    claims.forEachIndexed { index, claim ->
        claims.drop(index + 1).forEach { other ->
            if (other.intersects(claim)) {
                common.addAll(claim.pointsInCommon(other))
            }
        }
    }
    println("Total square inch overlapping: ${common.count()}")

    claims.first { claim -> claims.none { it.intersects(claim) } }
        .print { "ID of non-overlapping claim: ${it.id}" }

}

data class Claim(val id: Int, val x: Int, val y: Int, val width: Int, val height: Int) {

    val points = (x until x + width).flatMap { x -> 
                    (y until y + height).map { y -> Pair(x, y) } }

    fun pointsInCommon(other: Claim) = points.intersect(other.points)

    fun intersects(other: Claim): Boolean {
        if (id == other.id) {
            return false
        }

        val (left, right) = if (x < other.x) Pair(this, other) else Pair(other, this)
        val (top, bottom) = if (y < other.y) Pair(this, other) else Pair(other, this)
        return (right.x >= left.x && right.x <= left.x + left.width - 1) &&
                (bottom.y >= top.y && bottom.y <= top.y + top.height - 1)
    }

}