day24 and 25 completed.

day24/part1&2.java

@@ -0,0 +1,74 @@
+package code;
+
+import java.math.BigInteger;
+
+public class Main {
+    static int[] dxs = new int[]{13, 15, 15, 11, -7, 10, 10, -5, 15, -3, 0, -5, -9, 0}; // add x < >
+    static int[] dys = new int[]{6, 7, 10, 2, 15, 8, 1, 10, 5, 3, 5, 11, 12, 10};// add y < >
+    static int[] bs = new int[]{0, 0, 0, 0, 1, 0, 0, 1, 0, 1, 1, 1, 1, 1};// /1(0) or /26(1)
+
+    public static void main(String[] args) {
+        System.out.println(computeW(0, 0));
+        printZ(computeW(0, 0));
+    }
+    private static void printZ(String W) {
+        int z = 0;
+        for (int i = 0; i < 14; i++) {
+            z = next(z, W.charAt(i), dxs[i], dys[i], bs[i]);
+            System.out.println(z);
+        }
+    }
+    private static int next(int z, int w, int dx, int dy, int b) {
+        if (((z % 26) + dx) == w) {
+            return z / 26;
+        }
+        if (b == 0) {
+            return w + dy + 26 * z;
+        }
+        return -1;
+    }
+
+    private static int nextW(int z, int dx) {
+        int res = (z % 26) + dx;
+        if (res < 1 | res > 9)
+            return -1;
+        return (z % 26) + dx;
+    }
+
+    private static String computeW(int z, int i) {
+        int w;
+        if (i == 14) {
+            return "";
+        }
+        if (bs[i] == 1) {
+            w = nextW(z, dxs[i]);
+            if (w == -1)
+                return null;
+            z = next(z, w, dxs[i], dys[i], 1);
+            if (z == -1)
+                return null;
+            String nextWs = computeW(z, i + 1);
+            if (nextWs == null)
+                return null;
+            return w + nextWs;
+        }
+        BigInteger W = null;
+        int tmp;
+        for (int j = 1; j < 10; j++) {
+            w = j;
+            tmp = next(z, w, dxs[i], dys[i], 0);
+            if (tmp == -1)
+                continue;
+            String nextWs = computeW(tmp, i + 1);
+            if (nextWs == null)
+                continue;
+            if (W == null) {
+                W = new BigInteger(j + nextWs);
+            } else if (W.compareTo(new BigInteger(j + nextWs)) > 0) // part 1: <, part 2: >
+                W = new BigInteger(j + nextWs);
+        }
+        if (W == null)
+            return null;
+        return W.toString();
+    }
+}

day25/part1.py

@@ -0,0 +1,40 @@
+field = []
+next_field = []
+while True:
+    inp = input()
+    if inp == "end":
+        break
+    field.append(list(inp))
+    next_field.append(['.'] * len(inp))
+
+
+def check(f1, f2):
+    for i in range(len(f1)):
+        for j in range(len(f1[i])):
+            if f1[i][j] != f2[i][j]:
+                return False
+    return True
+
+
+count = 0
+n = len(field)
+m = len(field[0])
+while True:
+    for i in range(n):
+        for j in range(m):
+            if field[i][j] == '>' and field[i][(j + 1) % m] == '.':
+                next_field[i][(j + 1) % m] = '>'
+            elif field[i][j] == '>':
+                next_field[i][j] = '>'
+    for i in range(n):
+        for j in range(m):
+            if field[i][j] == 'v' and next_field[(i + 1) % n][j] == '.' and field[ (i + 1) % n][j] != 'v':
+                next_field[(i + 1) % n][j] = 'v'
+            elif field[i][j] == 'v':
+                next_field[i][j] = 'v'
+    count += 1
+    if check(field, next_field):
+        break
+    field = next_field
+    next_field = [['.' for _ in range(m)] for _ in range(n)]
+print(count)