new structure for 2018, added license information

2018/11/README.md

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+# 2018 Day 11: Chronal Charge 
+Copyright (c) Eric Wastl 
+#### [Direct Link](https://adventofcode.com/2018/day/11)
+
+## Part 1
+
+You watch the Elves and their sleigh fade into the distance as they head toward the North Pole.
+
+Actually, you're the one fading. The falling sensation returns.
+
+The low fuel warning light is illuminated on your wrist-mounted device. Tapping it once causes it to project a hologram of the situation: a **300x300** grid of fuel cells and their current power levels, some negative. You're not sure what negative power means in the context of time travel, but it can't be good.
+
+Each fuel cell has a coordinate ranging from **1 to 300** in both the X (horizontal) and Y (vertical) direction. In `X,Y` notation, the top-left cell is `1,1`, and the top-right cell is `300,1`.
+
+The interface lets you select **any 3x3 square** of fuel cells. To increase your chances of getting to your destination, you decide to choose the 3x3 square with the **largest total power**.
+
+The power level in a given fuel cell can be found through the following process:
+
+- Find the fuel cell's **rack ID**, which is its **X coordinate plus 10**.
+- Begin with a power level of the **rack ID** times the **Y coordinate**.
+- Increase the power level by the value of the **grid serial number** (your puzzle input).
+- Set the power level to itself multiplied by the **rack ID**.
+- Keep only the **hundreds digit** of the power level (so `12345` becomes 3; numbers with no hundreds digit become `0`).
+- **Subtract 5** from the power level.
+
+For example, to find the power level of the fuel cell at 3,5 in a grid with serial number `8`:
+
+- The rack ID is `3 + 10 = 13`.
+- The power level starts at `13 * 5 = 65`.
+- Adding the serial number produces `65 + 8 = 73`.
+- Multiplying by the rack ID produces `73 * 13 = 949`.
+- The hundreds digit of `949` is `9`.
+- Subtracting 5 produces `9 - 5 = 4`.
+
+So, the power level of this fuel cell is **`4`**.
+
+Here are some more example power levels:
+
+- Fuel cell at  `122, 79`, grid serial number `57`: power level `-5`.
+- Fuel cell at `217,196`, grid serial number `39`: power level  `0`.
+- Fuel cell at `101,153`, grid serial number `71`: power level  `4`.
+
+Your goal is to find the 3x3 square which has the largest total power. The square must be entirely within the 300x300 grid. Identify this square using the `X,Y` coordinate of its **top-left fuel cell**. For example:
+
+For grid serial number `18`, the largest total 3x3 square has a top-left corner of **`33,45`** (with a total power of `29`); these fuel cells appear in the middle of this 5x5 region:
+
+```
+-2  -4   4   4   4
+-4   4   4   4  -5
+ 4   3   3   4  -4
+ 1   1   2   4  -3
+-1   0   2  -5  -2
+```
+
+For grid serial number `42`, the largest 3x3 square's top-left is **`21,61`** (with a total power of `30`); they are in the middle of this region:
+
+```
+-3   4   2   2   2
+-4   4   3   3   4
+-5   3   3   4  -4
+ 4   3   3   4  -3
+ 3   3   3  -5  -1
+```
+
+**What is the `X,Y` coordinate of the top-left fuel cell of the 3x3 square with the largest total power?**
+
+## Part 2
+
+You discover a dial on the side of the device; it seems to let you select a square of **any size**, not just 3x3. Sizes from 1x1 to 300x300 are supported.
+
+Realizing this, you now must find the **square of any size with the largest total power**. Identify this square by including its size as a third parameter after the top-left coordinate: a 9x9 square with a top-left corner of `3,5` is identified as `3,5,9`.
+
+For example:
+
+- For grid serial number `18`, the largest total square (with a total power of `113`) is 16x16 and has a top-left corner of `90,269`, so its identifier is **`90,269,16`**.
+- For grid serial number `42`, the largest total square (with a total power of `119`) is 12x12 and has a top-left corner of `232,251`, so its identifier is **`232,251,12`**.
+
+**What is the X,Y,size identifier of the square with the largest total power?**

2018/11/code.py

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+""" https://adventofcode.com/2018/day/11 """
+
+def readFile():
+    with open(f"{__file__.rstrip('code.py')}input.txt", "r") as f:
+        return int(f.read())
+
+def getPowerlevel(x, y, serial):
+    rackId = x + 10
+    powerLevel = (rackId * y + serial) * rackId
+    return (int(powerLevel / 100) % 10) - 5
+
+def createGrid(serial):
+    grid = []
+    for j in range(1, 301):
+        row = []
+        for i in range(1, 301):
+            row.append(getPowerlevel(i, j, serial))
+        grid.append(row)
+    return grid
+
+def getBiggestField(grid, size):
+    maxSum = 0
+    maxCoords = (-1, -1)
+    for j in range(300 - size + 1):
+        for i in range(300 - size + 1):
+            curSum = 0
+            for n in range(size):
+                for m in range(size):
+                    curSum += grid[j + m][i + n]
+            if curSum > maxSum:
+                maxSum = curSum
+                maxCoords = (i + 1, j + 1)
+    return maxCoords, maxSum
+
+def getSat(grid):
+    # generates and returns summed-area table
+    sat = {}
+    size = len(grid)
+    for j in range(size):
+        for i in range(size):
+            value = grid[j][i] + sat.get(str((i - 1, j)), 0) 
+            value += sat.get(str((i, j - 1)), 0) - sat.get(str((i - 1, j - 1)), 0)
+            sat[str((i, j))] = value
+    return sat
+
+def getBiggestFieldSAT(sat, size):
+    maxSum = 0
+    maxCoords = (-1, -1)
+    for j in range(300 - size):
+        for i in range(300 - size):
+            ip, jp = i + size, j + size
+            curSum = sat[str((i, j))] + sat[str((ip, jp))] - sat[str((ip, j))] - sat[str((i, jp))]
+            if curSum > maxSum:
+                maxSum = curSum
+                maxCoords = (i + 2, j + 2)
+    return maxCoords, maxSum
+
+def part1(value):
+    grid = createGrid(value)
+    return getBiggestField(grid, 3)[0]
+
+def part2(value):
+    grid = createGrid(value)
+    sat = getSat(grid)
+    maxSum = 0
+    size = -1
+    maxCoords = (-1, -1)
+    for i in range(300):
+        curCoords, curSum = getBiggestFieldSAT(sat, i)
+        if curSum > maxSum:
+            maxSum = curSum
+            size = i
+            maxCoords = curCoords
+    return (maxCoords[0], maxCoords[1], size)
+
+if __name__ == "__main__":
+    value = readFile()
+    print(f"Part 1: {part1(value)}")
+    print(f"Part 2: {part2(value)}")

2018/11/input.txt

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+7857

2018/11/solution.txt

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+Part 1: (243, 16)
+Part 2: (231, 227, 14)