Searching programs

gistfile1.txt

/**
 * Linear search is a very simple search algorithm. 
 * In this type of search, a sequential search is made over all items one by one.
 * Every item is checked and if a match is found then that particular item is returned,
 * otherwise the search continues till the end of the data collection.
 * @param {*} arr : An array in which you want to search the value
 * @param {*} valueToSearch : value to be search in array
 */

function linearSearch(arr , valueToSearch){
    let arrLength = arr.length
    for(let i = 0; i < arrLength; i++){
        if(arr[i] === valueToSearch){
            return i;
        }
    }
    return -1
}

/**
 * Binary search is a fast search algorithm with run-time complexity of Ο(log n).
 * This search algorithm works on the principle of divide and conquer.
 * For this algorithm to work properly, the data collection should be in the sorted form.
 * @param {*} arr An array in which you want to search the value
 * @param {*} valueToSearch  value to be search in array
 */
function binarySearch(arr, valueToSearch){
    let lowerLimit = 0;
    let upperLimit = arr.length
    let midIndex = parseInt(( lowerLimit + upperLimit ) / 2 )

    while(true)
    {

        if( lowerLimit > upperLimit)
            return -1
        
        if( valueToSearch === arr[midIndex])
            return midIndex
        
        if(arr[midIndex] < valueToSearch){
            lowerLimit = midIndex + 1
        }
        else{
            upperLimit = midIndex - 1
        }
        midIndex = parseInt(( lowerLimit + upperLimit ) / 2 )
    }
}