Codility - Alpha 2010

codility-alpha2010.js

//Problem link: https://codility.com/programmers/challenges/alpha2010/
//Max score: 100% - Total time: 1 hr 02 mins

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//First solution - Score: 84%
//Link: https://codility.com/demo/results/trainingS8K2BU-VRE/
//Time: 17 mins

function solution(A) {
    for(var i = 0; i< A.length; i++) {
        var sub = A.slice(0, i);
        if(isMagic(sub, A)) {
            return i-1;
        }
    }
    return A.length - 1;
}

function isMagic(sub, A) {
    for(var j = 0; j < A.length; j++) {
        if(sub.indexOf(A[j]) < 0) {
            return false;
        }
    }
    return true;
}

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//Second solution - Score: 92%
//Link: https://codility.com/demo/results/trainingZVPKG9-QMD/
//Time: 27 mins

function solution(A) {
    var uniqueA = getUnique(A);
    var max;
    for(var i = 0; i < uniqueA.length; i++) {
        if(typeof(max) === 'undefined' || A.indexOf(uniqueA[i]) > max) {
            max = A.indexOf(uniqueA[i]);
        }       
    }
    return max;
}

function getUnique(a) {
    return a.filter(function(item, pos) {
        return a.indexOf(item) == pos;
    });
}


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//Last solution - Score: 100%
//Link: https://codility.com/demo/results/trainingPKDMA3-AMY/
//Time 18 mins

function solution(A) {
    var indexOfObject = getIndexOfObject(A);
    var max;
    for(var value in indexOfObject) {
        if(typeof(max) === 'undefined' || indexOfObject[value] > max) {
            max = indexOfObject[value];
        }
    }
    return max;
}

function getIndexOfObject(a) {
    var res = {};
    for(var i = 0; i < a.length; i++) {
        if(typeof(res[a[i]]) === 'undefined') {
            res[a[i]] = i;
        }
    }
    
    return res;
}