From c93b9430c1e4ff96c65cc70f65b29a58c49641cf Mon Sep 17 00:00:00 2001
From: David Wang <millimillenary@gmail.com>
Date: Sat, 4 Mar 2017 08:22:07 +1100
Subject: [PATCH] Add test: Kakuro.

kakuro_wikipedia: 9 guesses.
---
 tests/kakuro.rs | 105 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 105 insertions(+)
 create mode 100644 tests/kakuro.rs

diff --git a/tests/kakuro.rs b/tests/kakuro.rs
new file mode 100644
index 0000000..84cec7f
--- /dev/null
+++ b/tests/kakuro.rs
@@ -0,0 +1,105 @@
+//! Kakuro.
+//!
+//! https://en.wikipedia.org/wiki/Kakuro
+
+extern crate puzzle_solver;
+
+use puzzle_solver::{LinExpr,Puzzle,Solution,Val,VarToken};
+
+const SIZE: usize = 7;
+const X: Val = 0;
+type Board = [[Val; SIZE]; SIZE];
+type KakuroVars = Vec<Vec<Option<VarToken>>>;
+
+enum Rule {
+    H{ total: Val, y: usize, x1: usize, x2: usize },
+    V{ total: Val, x: usize, y1: usize, y2: usize },
+}
+
+fn make_kakuro(board: &[Rule]) -> (Puzzle, KakuroVars) {
+    let mut sys = Puzzle::new();
+    let mut vars = vec![vec![None; SIZE]; SIZE];
+
+    for rule in board.iter() {
+        let (total, x1, y1, x2, y2) = match rule {
+            &Rule::H{total, y, x1, x2} => (total, x1, y, x2, y),
+            &Rule::V{total, x, y1, y2} => (total, x, y1, x, y2),
+        };
+
+        let mut vec = Vec::new();
+        for y in y1..(y2 + 1) {
+            for x in x1..(x2 + 1) {
+                let var = vars[y][x].unwrap_or_else(|| {
+                    let var = sys.new_var_with_candidates(&[1,2,3,4,5,6,7,8,9]);
+                    vars[y][x] = Some(var);
+                    var
+                });
+
+                vec.push(var);
+            }
+        }
+
+        sys.all_different(&vec);
+        sys.equals(total, vec.iter().fold(LinExpr::from(0), |sum, &var| sum + var));
+    }
+
+    (sys, vars)
+}
+
+fn print_kakuro(dict: &Solution, vars: &KakuroVars) {
+    for y in 0..SIZE {
+        for x in 0..SIZE {
+            if let Some(var) = vars[y][x] {
+                print!(" {}", dict[var]);
+            } else {
+                print!(" .");
+            }
+        }
+        println!();
+    }
+}
+
+fn verify_kakuro(dict: &Solution, vars: &KakuroVars, expected: &Board) {
+    for y in 0..SIZE {
+        for x in 0..SIZE {
+            let val = vars[y][x].map_or(X, |var| dict[var]);
+            assert_eq!(val, expected[y][x]);
+        }
+    }
+}
+
+#[test]
+fn kakuro_wikipedia() {
+    let puzzle = [
+        Rule::H{ total:16, y:0, x1:0, x2:1 }, Rule::H{ total:24, y:0, x1:4, x2:6},
+        Rule::H{ total:17, y:1, x1:0, x2:1 }, Rule::H{ total:29, y:1, x1:3, x2:6},
+        Rule::H{ total:35, y:2, x1:0, x2:4 },
+        Rule::H{ total: 7, y:3, x1:1, x2:2 }, Rule::H{ total: 8, y:3, x1:4, x2:5},
+        Rule::H{ total:16, y:4, x1:2, x2:6 },
+        Rule::H{ total:21, y:5, x1:0, x2:3 }, Rule::H{ total: 5, y:5, x1:5, x2:6},
+        Rule::H{ total: 6, y:6, x1:0, x2:2 }, Rule::H{ total: 3, y:6, x1:5, x2:6},
+
+        Rule::V{ total:23, x:0, y1:0, y2:2 }, Rule::V{ total:11, x:0, y1:5, y2:6},
+        Rule::V{ total:30, x:1, y1:0, y2:3 }, Rule::V{ total:10, x:1, y1:5, y2:6},
+        Rule::V{ total:15, x:2, y1:2, y2:6 },
+        Rule::V{ total:17, x:3, y1:1, y2:2 }, Rule::V{ total: 7, x:3, y1:4, y2:5},
+        Rule::V{ total:27, x:4, y1:0, y2:4 },
+        Rule::V{ total:12, x:5, y1:0, y2:1 }, Rule::V{ total:12, x:5, y1:3, y2:6},
+        Rule::V{ total:16, x:6, y1:0, y2:1 }, Rule::V{ total: 7, x:6, y1:4, y2:6},
+    ];
+
+    let expected = [
+        [ 9, 7, X, X, 8, 7, 9 ],
+        [ 8, 9, X, 8, 9, 5, 7 ],
+        [ 6, 8, 5, 9, 7, X, X ],
+        [ X, 6, 1, X, 2, 6, X ],
+        [ X, X, 4, 6, 1, 3, 2 ],
+        [ 8, 9, 3, 1, X, 1, 4 ],
+        [ 3, 1, 2, X, X, 2, 1 ] ];
+
+    let (mut sys, vars) = make_kakuro(&puzzle);
+    let dict = sys.solve_any().expect("solution");
+    print_kakuro(&dict, &vars);
+    verify_kakuro(&dict, &vars, &expected);
+    println!("kakuro_wikipedia: {} guesses", sys.num_guesses());
+}