Add solution for sudoku strats: hidden singles

src/python/katas/py5kyu/sudoku_stategies_hidden_single.py

@@ -0,0 +1,30 @@
+"""Kata url: https://www.codewars.com/kata/65cd01dda11df609386d6ef9."""
+
+def groups(n: int) -> list[tuple[int, int]]:
+    return [(a,b) for a in (0,n,n*2) for b in (0,n,n*2)]
+
+
+def find_sol(s, val):
+    for gy, gx in groups(3):
+        coords = [(gx + x,gy + y) for y, x in groups(1) if s[gy + y][gx + x]]
+        if len(coords) == 1:
+            return coords[0][1], coords[0][0], val
+
+    for y in range(9):
+        if sum(s[y]) == 1:
+            return y, s[y].index(True), val
+        if sum(col := [s[x][y] for x in range(9)]) == 1:
+            return col.index(True), y, val
+    return False
+
+
+def progress(puzzle: list[list[int]], val = 1) -> tuple[int,int,int]:
+    s = [[(c == 0) for c in l] for l in puzzle]
+
+    coords = ((x,y) for y in range(9) for x in range(9) if puzzle[y][x] == val)
+    for x, y in coords:
+        for n in range(9):
+            s[y][n] = s[n][x] = False
+            s[y - (y%3) + (n%3)][x - (x % 3) + (n//3)] = False
+
+    return find_sol(s, val) or progress(puzzle, val = val + 1)