Merge pull request #30 from prettylittleminds/main

Reverse_A_String.c

String/Reverse_A_String.c

@@ -0,0 +1,65 @@
+//C Program to reverse a string:
+//Problem Statement: Given a string of size N. Reverse the string and display it.
+
+/* Algorithm- 
+To reverse a string :
+1. Start
+2. Declare a user-defined function revstr() 
+3. Run a for loop using the swapping logic in definition of revstr()
+4. Run another for loop for displaying the reversed string
+5. Under main() take user input for string.
+6. Call revstr() in main()
+7. Stop
+*/
+
+#include<stdio.h> //included the standard input/output header file
+
+//User-Defined Function Body containing logic:
+void revstr(char s[]) /*declaring and defining user-defined function, revstr() 
+                        which reverses a string by using swapping logic*/
+{
+    int a, n;         //initializing a counter variable 'a' and another 'n'
+    int temp = 0;     //initializing a temporary variable 'temp' to store the swapped value
+    for(n=0; s[n] != 0; n++); //a for loop to check if s[] is empty or not
+    for(a=0; a<n/2; a++) //another for loop for non-empty string, where swapping takes place
+    {
+        temp = s[a];
+        s[a]=s[n - 1 - a];
+        s[n - 1 - a] = temp;
+    }
+    for(a = 0; a < n; a++) //another for loop, to display the reversed string
+
+        putchar(s[a]);
+        printf(" is the reversed string .");
+    printf("\n");
+}
+
+
+//Main Function:
+int main(void)
+{
+    char s[1000]; 
+    printf("Insert the string to be reversed: ");
+    scanf("%s", s); //Taking input string from user
+    revstr(s); //Calling user-defined function revstr() from main()
+    return 0;
+}
+
+/*
+Test Case 1:
+Input: 
+Insert the string to be reversed: abc
+Output:
+cba is the reversed string .
+
+Test Case 2:
+Input: 
+Insert the string to be reversed: arushi
+Output: 
+ihsrua is the reversed string .
+
+Time Complexity: O(N) 
+Space Complexity: O(1)
+*/
+
+