From 44bfe9afa1615f901170d04971665504589b67a1 Mon Sep 17 00:00:00 2001
From: juan <juancloudcomputing@protonmail.com>
Date: Fri, 10 Dec 2021 23:51:00 +0800
Subject: [PATCH] Fix implementation of 2-4 and 2-3

---
 semester1/pset13/2-3-ArrayEX.c | 30 ++++++++------------
 semester1/pset13/2-4-ArrayEX.c | 51 +++++++++++++++++++++++++++++++++-
 2 files changed, 62 insertions(+), 19 deletions(-)
 mode change 120000 => 100644 semester1/pset13/2-4-ArrayEX.c

diff --git a/semester1/pset13/2-3-ArrayEX.c b/semester1/pset13/2-3-ArrayEX.c
index 58baa96..3750b5d 100644
--- a/semester1/pset13/2-3-ArrayEX.c
+++ b/semester1/pset13/2-3-ArrayEX.c
@@ -1,38 +1,33 @@
 #include <stdio.h>
-#include <stdlib.h>
 #include <string.h>
 #define MAX 100001
 
 void sort(char **arr, int n);
-void swap(char **arr1, char **arr2);
 
 int main(void) {
+  char str[MAX];
   int n;
   scanf("%d", &n);
+  char *arr[n];
   getchar();
-  // 2d array
-  char **str = malloc(sizeof(char *) * n);
-  // Buffer array
-  char *buffer = malloc(sizeof(char) * MAX);
 
+  // Get input
+  char ch;
+  int loc = 0;
   for (int i = 0; i < n; i++) {
-    fgets(buffer, MAX, stdin);
-    str[i] = malloc(strlen(buffer) + 1);
-    strcpy(str[i], buffer);
+    arr[i] = &str[loc];
+    while ((ch = getc(stdin)) != '\n') {
+      str[loc++] = ch;
+    }
+    str[loc++] = '\0';
   }
 
-  sort(str, n);
+  sort(arr, n);
 
   for (int i = 0; i < n; i++) {
-    printf("%s", str[i]);
+    printf("%s\n", arr[i]);
   }
 
-  // Free up memory
-  free(buffer);
-  for (int i = 0; i < n; i++) {
-    free(str[i]);
-  }
-  free(str);
   return 0;
 }
 
@@ -40,7 +35,6 @@ void sort(char **arr, int n) {
   for (int i = 0; i < n; i++) {
     for (int j = 0; j < n - 1; j++) {
       if (strcmp(arr[j], arr[j + 1]) > 0) {
-				// Why I can't use swap() here?
         char *tmp = arr[j];
         arr[j] = arr[j + 1];
         arr[j + 1] = tmp;
diff --git a/semester1/pset13/2-4-ArrayEX.c b/semester1/pset13/2-4-ArrayEX.c
deleted file mode 120000
index 6104f4b..0000000
--- a/semester1/pset13/2-4-ArrayEX.c
+++ /dev/null
@@ -1 +0,0 @@
-2-3-ArrayEX.c
\ No newline at end of file
diff --git a/semester1/pset13/2-4-ArrayEX.c b/semester1/pset13/2-4-ArrayEX.c
new file mode 100644
index 0000000..caf5238
--- /dev/null
+++ b/semester1/pset13/2-4-ArrayEX.c
@@ -0,0 +1,50 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#define MAX 1001
+
+void sort(char **arr, int n);
+void swap(char **arr1, char **arr2);
+
+int main(void) {
+  int n;
+  scanf("%d", &n);
+  getchar();
+  // 2d array
+  char **str = malloc(sizeof(char *) * n);
+  // Buffer array
+  char *buffer = malloc(sizeof(char) * MAX);
+
+  for (int i = 0; i < n; i++) {
+    fgets(buffer, MAX, stdin);
+    str[i] = malloc(strlen(buffer) + 1);
+    strcpy(str[i], buffer);
+  }
+
+  sort(str, n);
+
+  for (int i = 0; i < n; i++) {
+    printf("%s", str[i]);
+  }
+
+  // Free up memory
+  free(buffer);
+  for (int i = 0; i < n; i++) {
+    free(str[i]);
+  }
+  free(str);
+  return 0;
+}
+
+void sort(char **arr, int n) {
+  for (int i = 0; i < n; i++) {
+    for (int j = 0; j < n - 1; j++) {
+      if (strcmp(arr[j], arr[j + 1]) > 0) {
+        // Why I can't use swap() here?
+        char *tmp = arr[j];
+        arr[j] = arr[j + 1];
+        arr[j + 1] = tmp;
+      }
+    }
+  }
+}