From 7cdf4dcae66e304011e24f42209dc09751468faf Mon Sep 17 00:00:00 2001
From: Camden Dixie O'Brien <cdo@wip.sh>
Date: Sat, 22 Mar 2025 13:33:38 +0000
Subject: [PATCH] Identify mines on edges

---
 main.c | 27 +++++++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/main.c b/main.c
index 393f70f..06f832f 100644
--- a/main.c
+++ b/main.c
@@ -13,6 +13,18 @@
 
 enum { UNKNOWN = 0xfe, KILLER = 0xfd };
 
+static void setadj(puzz_t field, int x, int y, uint8_t from, uint8_t to)
+{
+	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
+			    || (xp == x && yp == y))
+				continue;
+			field[xp][yp] = field[xp][yp] == from ? to : field[xp][yp];
+		}
+	}
+}
+
 int main(void)
 {
 	struct timeval tv;
@@ -28,11 +40,22 @@ int main(void)
 	puzz_t field;
 	memset(field, UNKNOWN, sizeof(field));
 
-	const int x = rand() % WIDTH;
-	const int y = rand() % HEIGHT;
+	int x = rand() % WIDTH;
+	int y = rand() % HEIGHT;
 	if (probe(x, y, field) == DEAD) {
 		field[x][y] = KILLER;
 		fprintf(stderr, "Dead\n");
+	} else {
+		for (y = 0; y < HEIGHT; ++y) {
+			for (x = 0; x < WIDTH; ++x) {
+				if (field[x][y] == UNKNOWN || field[x][y] == MINE)
+					continue;
+				const int mines = countadj(field, x, y, MINE);
+				const int unknowns = countadj(field, x, y, UNKNOWN);
+				if (mines + unknowns == field[x][y])
+					setadj(field, x, y, UNKNOWN, MINE);
+			}
+		}
 	}
 
 	putchar('\n');