so i found a solution for this mathematical problem which is this one
function getMaxSubSum(arr) {
let maxSum = 0;
let partialSum = 0;
for (let item of arr) { // for each item of arr
partialSum += item; // add it to partialSum
maxSum = Math.max(maxSum, partialSum); // remember the maximum
if (partialSum < 0) partialSum = 0; // zero if negative
}
return maxSum;
}
alert ( getMaxSubSum([1,-2,3,9,-9,6]) )
BUT i want to achieve it with another way and im trying this code
function kadane () {
arr = [1,-2,3,9,-9,6]
let maxSub = maxGlobal = arr[0]
for (i=3 ; i<arr.length-1; i++ ) {
maxSub = Math.max(arr[i], maxSub + arr[i])
if (maxSub > maxGlobal) {
maxSub = maxGlobal
}
}
return maxSub
}
alert (kadane())
does anyone know what im doing wrong?
Your solution were really close !
Here you inverted maxSub and maxGlobal in the if section.
Also, I don't know why but your for loop where starting at 3 instead of 1.
Here is your working example
function kadane(arr) {
let maxSub = arr[0]
let maxGlobal = arr[0]
for (i = 1; i < arr.length; i++) {
maxSub = Math.max(arr[i], maxSub + arr[i])
if (maxSub > maxGlobal) {
maxGlobal = maxSub
}
}
return maxGlobal
}
const arr = [1, -2, 3, 9, -9, 6]
alert(kadane(arr))Also, note that you could also have checked the maximum of 2 numbers consecutively.
Example using Array#reduce
function kadane(arr) {
return arr.reduce((acc, curr, index) => {
if(index === 0) return curr > 0 ? curr : 0
else {
const sum = curr + arr[index-1]
return sum > acc ? sum : acc
}
}, 0)
}
console.log(kadane([1, -2, 3, 9, -9, 6]))
console.log(kadane([-1, -2, -3, -4, -5, -6]))Collected from the Internet
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