53 lines
1.3 KiB
JavaScript
53 lines
1.3 KiB
JavaScript
//Recursive Method
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/*Arguments to Function
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arr - array ( Sorted Only )
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low - lower index of array (0)
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high - max index of array (length of array - 1 )
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item = Element to be searched .
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*/
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function binary_recurrence(arr, low, high, item) {
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// Base Case for the termination of Recursion
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if(low > high) {
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return -1 ; //Item is not present in the Array
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}
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// Calculating Mid Index
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let mid = Math.floor((low+high)/2) ;
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//Equation Middle Element with the item to be searched
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if(arr[mid] == item ){
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// Middle Element equal to the Item
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// We found Element at the mid Index
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return mid ;
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}
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else if( arr[mid] > item ){
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// Item is less than the middle Element
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// Ignore the Right Half , as right half contains elements greater than middle element and so item too .
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// Make a recursive call to the left Half
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return binary_recurrence(arr,low,mid-1,item);
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}
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else {
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//Item is greater than the middle Element
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//Ignore the Left Half ,as left half contains element less than middle element and so item too .
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//Make recursive call to the right Half
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return binary_recurrence(arr,mid+1,high,item);
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}
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}
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console.log(binary_recurrence([1,3,5,7,8,9], 0, 5, 7)); //returns 3 , Found at Index 3
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console.log(binary_recurrence([1,3,5,7,8,9], 0, 5, 10)); //returns -1 , 10 is not present in array
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