Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly
Sign up
Appearance settings

Added Fractional Knapsack Algorithm #725

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
ritiksingh2 wants to merge 1 commit into TheAlgorithms:master from ritiksingh2:master
Closed
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
78 changes: 78 additions & 0 deletions Dynamic-Programming/fractionalKnapsack.js
View file Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,78 @@
/* 0-1 knapsack problem

items: an array of {w: v:} (where 'w' stands for weight, and 'v' stands for value)
capacity: a positive integer number
Will return max sum value that can reach, and the chosen subset to add up to the value.
Example:
var items = [{w:3,b:10},{w:1,b:3},{w:2,b:9},{w:2,b:5},{w:1,b:6}];
var capacity = 6;
console.log(knapsack(items, capacity));
will return
{ maxValue: 25,
subset: [ { w: 1, v: 6 }, { w: 2, v: 9 }, { w: 3, v: 10 } ] }
*/

function knapsack(items, capacity) {
var memo = []

// Filling the sub-problem solutions grid.
for (var i = 0; i < items.length; i++) {
// Variable 'cap' is the capacity for sub-problems. In this example, 'cap' ranges from 1 to 6.
var row = []
for (var cap = 1; cap <= capacity; cap++) {
row.push(getSolution(i, cap))
}
memo.push(row)
}

return getLast()

function getLast() {
var lastRow = memo[memo.length - 1]
return lastRow[lastRow.length - 1]
}

function getSolution(row, cap) {
const NO_SOLUTION = { maxValue: 0, subset: [] }

var col = cap - 1
var lastItem = items[row]

var remaining = cap - lastItem.w

var lastSolution = row > 0 ? memo[row - 1][col] || NO_SOLUTION : NO_SOLUTION

var lastSubSolution =
row > 0 ? memo[row - 1][remaining - 1] || NO_SOLUTION : NO_SOLUTION

if (remaining < 0) {
return lastSolution
}

var lastValue = lastSolution.maxValue
var lastSubValue = lastSubSolution.maxValue

var newValue = lastSubValue + lastItem.v
if (newValue >= lastValue) {
var _lastSubSet = lastSubSolution.subset.slice()
_lastSubSet.push(lastItem)
return { maxValue: newValue, subset: _lastSubSet }
} else {
return lastSolution
}
}
}

// test
var items = [
Copy link
Member

@raklaptudirm raklaptudirm Oct 4, 2021

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Remove these statements and add a test file instead.

josecarlosweb reacted with thumbs up emoji
{ w: 70, v: 135 },
{ w: 73, v: 139 },
{ w: 77, v: 149 },
{ w: 80, v: 150 },
{ w: 82, v: 156 },
{ w: 87, v: 163 },
{ w: 90, v: 173 }
]

var capacity = 750
console.log(knapsack(items, capacity))

AltStyle によって変換されたページ (->オリジナル) /