Codility demo tests solutions

codility-demo.js

// 100-score solution for http://codility.com/demo/take-sample-test/

function equi(array) {
    var i, 
        len = array.length, 
        sum = 0,
        leftSum = 0,
        rightSum;

    for (i = 0; i < len; i++) {
        sum += array[i];
    }

    for (i = 0; i < len; i++) {
        rightSum = sum - leftSum - array[i];

        if (leftSum === rightSum) {
            return i;
        }

        leftSum += array[i];
    }

    return -1;
}

// 100-score solution for http://codility.com/demo/take-sample-test/ps/

function ps(array) {
    var i,
        len = array.length,
        memo = {},
        result = 0,
        value;
        
    for (i = 0; i < len; i++) {
        value = array[i];
        
        if (!memo[value]) {
            result = i;
            memo[value] = true;
        }
    }
    return result;
}