修改文件结构。

POP/02/Exercise03.c

@@ -0,0 +1,9 @@
+#include <stdio.h>
+int main() {
+    char input, prev, next;
+    input = getchar();
+    prev = input - 1;
+    next = input + 1;
+    printf("ASCII number: %d, Previous char: %c, Next char: %c", input, prev, next);
+    return 0;
+}