complete day4 part 1

day4.jai

@@ -12,7 +12,56 @@ sample :: #string END
 END
 
 main :: () {
+    print("@: %\n", #char "@");
+    print(".: %\n", #char ".");
+    content := read_entire_file("day4.input");
 
+    solve_first(content);
+}
+
+solve_first :: (input: string) {
+    all_lines := split(input, #char "\n");
+    lines: [..]string;
+    for line: all_lines {
+        if line.count == 0 continue;
+        array_add(*lines, line);
+    }
+    assert(lines[0].count != 0);
+    line_length := lines[0].count;
+    removable := 0;
+    for line, line_index: lines {
+        if line.count == 0 continue;
+        for char, char_index: line {
+            if char == #char "." continue;
+            surrounding_chars: [8]u8;
+            surrounding_chars_index := 0;
+            for dy: -1..1 {
+                for dx: -1..1 {
+                    if dx == 0 && dy == 0 continue;
+                    defer surrounding_chars_index += 1;
+                    x := char_index + dx;
+                    if x < 0 || line.count <= x continue;
+                    y := line_index + dy;
+                    if y < 0 || lines.count <= y continue;
+                    surrounding_chars[surrounding_chars_index] = lines[y][x];
+                }
+            }
+            if array_count(surrounding_chars, (char: u8) -> bool { return char == #char "@"; }) < 4 {
+                removable += 1;
+            }
+        }
+    }
+    print("%\n", removable);
+}
+
+array_count :: (arr: []$T, f: (t: T) -> bool) -> int {
+    total := 0;
+    for arr {
+        if f(it) total += 1;
+    }
+    return total;
 }
 
 #import "Basic";
+#import "File";
+#import "String";