Add first exercises of chapter 04

c_primer_plus/chapter04/01.c

@@ -0,0 +1,18 @@
+#include <stdio.h>
+
+
+
+int main (void) {
+
+  char first_name[20];
+  char last_name[20];
+
+  printf("Your first name: ");
+  scanf("%s", first_name);
+  printf("Your last name: ");
+  scanf("%s", last_name);
+  printf("Your name is %s, %s\n", last_name, first_name);
+
+  return 0;
+
+}

c_primer_plus/chapter04/02.c

@@ -0,0 +1,19 @@
+#include <stdio.h>
+#include <string.h>
+
+
+
+int main (void) {
+
+  char first_name[20];
+
+  printf("Your first name: ");
+  scanf("%s", first_name);
+
+  printf("Your name: \"%s\"\n", first_name);
+  printf("Your name: \"%20s\"\n", first_name);
+  printf("Your name: \"%*s\"\n", (int)(strlen(first_name)+3), first_name);
+
+  return 0;
+
+}