Submission #3420216

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Source Code Expand

import strutils
import sequtils
import algorithm
import math
import queues
import tables
import sets
import logging
import future

const INF* = int(1e18 + 373)

proc readSeq*(): seq[string] = stdin.readLine().strip().split()
proc readSeq*(n: Natural): seq[string] =
  result = newSeq[string](n)
  for i in 0..<n:
    result[i] = stdin.readLine().strip()

proc readInt1*(): int = readSeq().map(parseInt)[0]
proc readInt2*(): (int, int) =
  let a = readSeq().map(parseInt)
  return (a[0], a[1])
proc readInt3*(): (int, int, int) =
  let a = readSeq().map(parseInt)
  return (a[0], a[1], a[2])
proc readInt4*(): (int, int, int, int) =
  let a = readSeq().map(parseInt)
  return (a[0], a[1], a[2], a[3])

type seq2*[T] = seq[seq[T]]
proc newSeq2*[T](n1, n2: Natural): seq2[T] = newSeqWith(n1, newSeq[T](n2))

#------------------------------------------------------------------------------#
proc eval(s: string): int =
  var zeroInd = @[ -1 ]
  for i in 0..<s.len():
    if s[i] == '0':
      zeroInd.add(i)
  zeroInd.add(s.len())

  var ones = newSeq[int]()
  for i in 0..<zeroInd.len() - 1:
    ones.add(zeroInd[i + 1] - zeroInd[i] - 1)

  let k = ones.len()
  if k == 1:
    return 0

  var dp = newSeq2[int](k + 1, 3)
  dp[k][0] = 0
  dp[k][1] = 0
  dp[k][2] = 0
  dp[k - 1][0] = 0
  dp[k - 1][1] = 0
  dp[k - 1][2] = 0
  for i in countdown(k - 2, 0):
    let ll = ones[i]
    let rr = ones[i + 1]

    dp[i][0] = dp[i + 1][0]
    dp[i][0] = max(dp[i][0], ll + dp[i + 1][1])
    dp[i][0] = max(dp[i][0], rr + dp[i + 2][0])
    if rr >= 2:
      dp[i][0] = max(dp[i][0], (rr - 1) + dp[i + 1][2])

    dp[i][1] = dp[i + 1][0]
    if ll >= 2:
      dp[i][1] = max(dp[i][1], (ll - 1) + dp[i + 1][1])
      dp[i][1] = max(dp[i][1], rr + dp[i + 2][0])
      if rr >= 2:
        dp[i][1] = max(dp[i][1], (rr - 1) + dp[i + 1][2])

    dp[i][2] = dp[i + 1][0]
    dp[i][2] = max(dp[i][2], 1 + dp[i + 1][1])
    dp[i][2] = max(dp[i][2], rr + dp[i + 2][0])
    if rr >= 2:
      dp[i][2] = max(dp[i][2], (rr - 1) + dp[i + 1][2])

  # echo s
  # echo ones
  # echo dp[0][0]
  # echo ""
  return dp[0][0]

proc main() =
  let n = readInt1()
  let s = stdin.readLine()

  var sec = newSeq[string](0)

  var i = 0
  while i < n and s[i] == '0':
    i += 1

  while i < n:
    var j = i
    while j < n:
      if s[j] == '0' and (j + 1 >= n or s[j + 1] == '0'):
        break
      j += 1

    sec.add(s[i..<j])

    i = j
    while i < n and s[i] == '0':
      i += 1

  var ans = 0
  for s in sec:
    ans += s.eval()
  echo ans

main()

Submission Info

Compile Error

Hint: system [Processing]
Hint: Main [Processing]
Hint: strutils [Processing]
Hint: parseutils [Processing]
Hint: sequtils [Processing]
Hint: algorithm [Processing]
Hint: math [Processing]
Hint: times [Processing]
Hint: queues [Processing]
Hint: tables [Processing]
Hint: hashes [Processing]
Hint: etcpriv [Processing]
Hint: sets [Processing]
Hint: os [Processing]
Hint: posix [Processing]
Hint: logging [Processing]
lib/pure/logging.nim(128, 22) Hint: 'Exception' is declared but not used [XDeclaredButNotUsed]
Hint: future [Processing]
Hint: macros [Processing]
Hint:  [Link]
Hint: operation successful (24901 lines compiled; 2.837 sec total; 25.256MB; Release Build) [SuccessX]

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