Merge pull request #374 from ArchismwanChatterjee/main

Added cipher algo and address comparison of variables

Author: akkupy

c/ROT13_cipher.c

@@ -0,0 +1,37 @@
+/*
+WAP to read any string/message from the user irrespective of the case
+Decode the string by shifting each alphabet 13 places.
+If the alphabet is 'Z' then it would be 'g' but make it in a way so that it gives 'M' that means keep a note of the case
+This is ROT13 Cipher Algorithm
+*/
+
+#include <stdio.h>
+#include <string.h>
+
+void decode_rot13(char *str)
+{
+    int i;
+    for (i = 0; str[i] != '\0'; i++)
+    {
+        if (str[i] >= 'A' && str[i] <= 'Z')
+        {
+            str[i] = (((str[i] - 'A') + 13) % 26) + 'A';
+        }
+        else if (str[i] >= 'a' && str[i] <= 'z')
+        {
+            str[i] = (((str[i] - 'a') + 13) % 26) + 'a';
+        }
+    }
+}
+
+int main()
+{
+    char str[] = "CNFFJBEq";
+    decode_rot13(str);
+    printf("Decoded string: %s\n", str);
+    return 0;
+}
+/*
+OUTPUT
+Decoded string: PASSWORD
+*/

c/address_comparison.c

@@ -0,0 +1,26 @@
+// WAP to compare addresses of 2 variables and display appropriate message
+
+#include <stdio.h>
+
+int main()
+{
+    int x, *p;
+    int y, *q;
+    p = &x;
+    q = &y;
+    printf("Address : %x \n", p);
+    printf("Address : %x \n", q);
+    if (p == q)
+        printf("Equal");
+    else
+        printf("Not Equal");
+    return 0;
+}
+/*
+OUTPUT
+
+Address : 61ff14
+Address : 61ff10
+Not Equal
+
+*/

c/caesar_cipher.c

@@ -0,0 +1,77 @@
+/*
+WAP to read any string/message from the user in uppercase
+Encrypt the string by shifting each alphabet x(<256) places.
+If the alphabet is 'Z' and x is 3 then it would be ']' but make it in a way so that it gives 'C'.
+This is CaesarCipher Algorithm
+*/
+
+#include <stdio.h>
+#include <string.h>
+#include <math.h>
+#include <ctype.h>
+
+int main()
+{
+
+    char ch[100], s[100];
+    int x, j = 0;
+
+    printf("Type your code: \n");
+    scanf("%s", &ch);
+
+    while (s[j]) // converting to uppercase
+    {
+        s[j] = toupper(ch[j]);
+        j++;
+    }
+
+    printf("Original code is \n");
+    for (int i = 0; i < strlen(s); i++)
+    {
+        printf("%c", s[i]);
+    }
+
+    printf("\n Enter any number < 256 \n");
+    scanf("%d", &x);
+
+    printf("\n Encrypted code is \n");
+
+    if (x < 256)
+    {
+        for (int i = 0; i < strlen(s); i++)
+        {
+            int a = fabs((int)s[i] + x);
+
+            if (a > (int)'Z')
+            {
+                int d = (a - (int)'Z') % 26;
+                if (d != 0)
+                    s[i] = (char)(64 + d);
+                else
+                    s[i] = 'Z';
+            }
+        }
+
+        for (int i = 0; i < strlen(s); i++)
+        {
+            printf("%c", s[i]);
+        }
+    }
+    else
+        printf("Wrong input");
+    return 0;
+}
+
+/*
+OUTPUT:
+
+Type your code:
+ABCD
+Original code is
+ABCD
+Enter any number < 256
+58
+Encrypted code is
+GHIJ
+
+*/