findNb.js

/**
 * Description:
 * Your task is to construct a building which will be a pile of n cubes. The cube at the bottom will have a volume of n^3, the cube above will have volume of (n-1)^3 and so on until the top which will have a volume of 1^3.
 *
 * You are given the total volume m of the building. Being given m can you find the number n of cubes you will have to build?
 *
 * The parameter of the function findNb (find_nb, find-nb, findNb) will be an integer m and you have to return the integer n such as n^3 + (n-1)^3 + ... + 1^3 = m if such a n exists or -1 if there is no such n.
 *
 * Examples:
 *
 * findNb(1071225) --> 45
 * findNb(91716553919377) --> -1
 */
function findNb(m) {
    let cacheSum = 0
    for (n = 1; n < m; n++) {
        cacheSum += Math.pow(n, 3)
        if (cacheSum > m){
            break;
        }

        if (cacheSum == m) {
            return n
        }
    }

    return (-1);
}