24 lines
958 B
JavaScript
24 lines
958 B
JavaScript
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function binarySearch(value, list) {
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let first = 0; //left endpoint
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let last = list.length - 1; //right endpoint
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let position = -1; // After looping if the search item is not found, we will return -1
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let found = false; // When item is found we set its value to true
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let middle;
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while (found === false && first <= last) {
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middle = Math.floor((first + last)/2);
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if (list[middle] == value) { // If the element is present at the middle itself
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found = true;
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position = middle;
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} else if (list[middle] > value) { //if in lower half
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last = middle - 1;
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} else { //in in upper half
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first = middle + 1;
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}
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}
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return position;
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}
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console.log(binarySearch(6,[2, 6, 8])); //expected output = 1
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console.log(binarySearch(10,[2, 3, 10, 14])); //expected output = 2
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console.log(binarySearch(1,[2, 6, 8])); //expected output = -1
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