43 lines
1.1 KiB
C
43 lines
1.1 KiB
C
/* Program to demonstrate recursive binary search */
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/* We assume that the array is sorted in ascending order */
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#include <stdio.h>
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#include <conio.h>
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int binary(int x[ ], int low, int high, int key) ;
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void main()
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{
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int i, n, x[20], key ;
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clrscr() ;
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printf("Enter the number of elements: ") ;
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scanf("%d",&n) ;
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printf("Enter the elements:\n") ;
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for(i=0 ; i<n ; i++)
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scanf("%d",&x[i]) ;
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printf("Enter the element to be searched: ") ;
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scanf("%d",&key) ;
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i=binary(x,0,n-1,key) ;
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if(i==-1)
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printf("%d not found.", key) ;
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else
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printf("%d found at position %d.", key,i) ;
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getch() ;
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}
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int binary(int x[ ], int low, int high, int key)
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{
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int mid ;
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if(low>high)
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return -1 ;
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mid=(low+high)/2 ;
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if(key==x[mid])
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return mid ;
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else if(key<x[mid])
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return (binary(x,low,mid-1,key)) ;
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else
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return (binary(x,mid+1,high,key)) ;
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}
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/* The condition (key<x[mid]) will become (key>x[mid]) if array x is in descending order */
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