We use cookies to ensure you have the best browsing experience on our website. Please read our cookie policy for more information about how we use cookies.
  1. Prepare
  2. Data Structures
  3. Arrays
  4. Array Manipulation
  5. Discussions

Array Manipulation

  • arrobaunferna
     + 0 comments

    You cannot directly sum each item in range because you will get a Time Exceeded Exception.

    Instead, use prefix sum technique: 

    // Swift
func arrayManipulation(n: Int, queries: [[Int]]) -> Int {
    // 1-indexed
    var operations: [Int] = Array(repeating: 0, count: n + 1)

    for query in queries {
        let a = query[0]
        let b = query[1]
        let k = query[2]

        operations[a - 1] += k
        operations[b] -= k
    }
    
    var maxValue = 0
    var currentSum = 0
    for value in operations {
        currentSum += value
        maxValue = max(maxValue, currentSum)
    }
    
    return maxValue
}