From 78c0ad81e20290512667d877413a5dae5174ee26 Mon Sep 17 00:00:00 2001
From: Camden Dixie O'Brien <cobrien@witekio.com>
Date: Thu, 6 Mar 2025 21:13:49 +0000
Subject: [PATCH] Implement probes

---
 puzz.c | 41 +++++++++++++++++++++++++++++++++++++++++
 puzz.h |  2 ++
 2 files changed, 43 insertions(+)

diff --git a/puzz.c b/puzz.c
index f86dbb7..895e595 100644
--- a/puzz.c
+++ b/puzz.c
@@ -5,12 +5,16 @@
 
 #include "puzz.h"
 
+#include <assert.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
+enum { NO = 0, YES = 1 };
+
 static puzz_t soln;
+static puzz_t scanned;
 
 void gen(void)
 {
@@ -50,3 +54,40 @@ void print(void)
 	}
 	putchar('\n');
 }
+
+static void scan_copy(int x, int y, puzz_t out)
+{
+	assert(x >= 0 && x < WIDTH);
+	assert(y >= 0 && y < HEIGHT);
+
+	out[x][y] = soln[x][y];
+	scanned[x][y] = YES;
+
+	if (soln[x][y] != 0)
+		return;
+
+	for (int yp = y - 1; yp < y + 2; ++yp) {
+		for (int xp = x - 1; xp < x + 2; ++xp) {
+			if (xp < 0 || xp >= WIDTH || yp < 0 || yp >= HEIGHT
+			    || scanned[xp][yp] == YES)
+				continue;
+			scan_copy(xp, yp, out);
+		}
+	}
+}
+
+status_t probe(int x, int y, puzz_t out)
+{
+	printf("Probing: %d,%d\n", x, y);
+
+	assert(x >= 0 && x < WIDTH);
+	assert(y >= 0 && y < HEIGHT);
+
+	if (soln[x][y] == MINE)
+		return DEAD;
+
+	memset(scanned, NO, sizeof(scanned));
+	scan_copy(x, y, out);
+
+	return OK;
+}
diff --git a/puzz.h b/puzz.h
index 4a639e3..aa615f4 100644
--- a/puzz.h
+++ b/puzz.h
@@ -15,8 +15,10 @@
 enum { MINE = 0xff };
 
 typedef uint8_t puzz_t[WIDTH][HEIGHT];
+typedef enum { DEAD, OK } status_t;
 
 void gen(void);
 void print(void);
+status_t probe(int x, int y, puzz_t out);
 
 #endif