inventry_update.ts

// merge two sorted arrays
// algorithm from 
// - Sorting by merging, The art of computer programing 
function merge(x:any[], y:any[]) {
    
    const iLen = x.length,
          jLen = y.length;
    
    let i = 0,
        j = 0,
        k = 0,
        z = [];
        
    while (i < iLen && j < jLen) {
        if (x[i] <= y[j]) {
            z[k] = x[i];
            k += 1;
            i += 1;
            // goto M2
        } else {
            z[k] = y[j];
            k += 1;
            j += 1;
            // goto M2
        }
    }
       
    if (j < jLen) {
        z = z.concat(
            y.slice(j)
        );
    }
    
    if (i < iLen) {
        z = z.concat(
            x.slice(i)
        );
    }
    
    return z;
}

function updateInventory(arr1:any[], arr2:any[]) {
    const compareFn = (a:any[], b:any[]) => {
        if (a[1] === b[1]) {
            return 0;
        } else if (a[1] > b[1]) {
            return 1;
        } else {
            return -1;
        }
    }
    
    return arr2.sort(compareFn);
}

// Example inventory lists
var curInv = [
    [21, "Bowling Ball"],
    [2, "Dirty Sock"],
    [1, "Hair Pin"],
    [5, "Microphone"]
];

var newInv = [
    [2, "Hair Pin"],
    [3, "Half-Eaten Apple"],
    [67, "Bowling Ball"],
    [7, "Toothpaste"]
];

console.log(
    updateInventory(
        curInv,
        newInv
    )
)