Write a program to search a character in a string using binary search

with function:

1. #include <stdio.h>
2. #include <string.h>
3. 
   
4. int func(char str[100][100],int start,int end,char key[40])
5. {
6.     while(start <= end)
7.     {
8.         int mid = (start+end)/2;
9.         if (strcmp(key, str[mid])==0)
10.         {
11.             printf("key found at the position %d\n", mid+1);
12.             return 0;
13.         }
14.         else if
15.                 (strcmp(key, str[mid])>0)
16.         {
17.             end = end;
18.             start = mid+1;
19.         }
20. 
    
21.         else
22.         {
23.             start=start;
24.             end = mid-1;
25.         }
26.     }
27.     return -1;
28. 
    
29. }
30. int main()
31. {
32.     int i, n, start, end, mid;
33.     char str[100][100], key[40];
34. 
    
35.     printf("Please enter the number of string to be stored : ");
36.     scanf("%d",&n);
37. 
    
38.     printf("Enter the string in ascending order\n");
39. 
    
40.     for(i=0; i<=n-1; i++)
41.     {
42.         scanf("%s", &str[i]);
43.     }
44. 
    
45.     printf("Enter the string to be searched : ");
46.     scanf("%s", &key);
47. 
    
48.     start = 0;
49.     end = n-1;
50.     if(func(str,start,end,key)==-1)
51.         printf("Failed\n");
52.     return 0;
53. }

with recursion:

1. #include <stdio.h>
2. #include <string.h>
3. 
   
4. int recursion(char str[100][100],int start,int end,char key[40])
5. {
6.     if(start>end)
7.         return -1;
8.     int mid = (start+end)/2;
9.     if(strcmp(key, str[mid])==0)
10.     {
11.         printf("key found at the position %d\n", mid+1);
12.         return 0;
13.     }
14.     else if(strcmp(key, str[mid])>0)
15.     {
16.         recursion(str,mid+1,end,key);
17.     }
18.     else
19.     {
20.         recursion(str,start,mid-1,key);
21.     }
22. 
    
23. }
24. int main()
25. {
26.     int i, n, start, end, mid;
27.     char str[100][100], key[40];
28. 
    
29.     printf("Please enter the number of string to be stored : ");
30.     scanf("%d",&n);
31. 
    
32.     printf("Enter the string in ascending order\n");
33. 
    
34.     for(i=0; i<=n-1; i++)
35.     {
36.         scanf("%s", &str[i]);
37.     }
38. 
    
39.     printf("Enter the string to be searched : ");
40.     scanf("%s", &key);
41. 
    
42.     start = 0;
43.     end = n-1;
44.     if(recursion(str,start,end,key)==-1)
45.         printf("Failed\n");
46.     return 0;
47. }