2020-08: Handheld Halting

masterDF <- read.csv("input.csv")

Part 1

df <- masterDF
df$ipa <- NA
df$ipa[1] <- 0
acc <- 0
r <- 1
flag <- TRUE

while(flag == TRUE) {
  if(as.character(df$ope[r]) == "acc" & r <= 626 & r >= 1) {
    acc <- acc + df$arg[r]
    flag <- is.na(df$ipa[r + 1])
    df$ipa[r + 1] <- r
    r <- r + 1
    }
  else if(as.character(df$ope[r]) == "jmp" & r + df$arg[r] <= 626 & r + df$arg[r] >= 1) {
    flag <- is.na(df$ipa[r + df$arg[r]])
    df$ipa[r + df$arg[r]] <- r
    r <- r + df$arg[r]
    }
  else if(as.character(df$ope[r]) == "nop" & r <= 626 & r >= 1) {
    flag <- is.na(df$ipa[r + 1])
    df$ipa[r + 1] <- r
    r <- r + 1
    }
}

acc

[1] 1317

Part 2

for(i in 1:626) {
  df <- masterDF
  
  df$ipa <- NA
  df$ipa[1] <- 0
  
  acc <- 0
  r <- 1
  
  flag <- TRUE
  breakFlag <- FALSE
  
  if(as.character(df$ope[i]) == "nop")
    df$ope[i] <- "jmp"
  else if(as.character(df$ope[i]) == "jmp")
    df$ope[i] <- "nop"
  
  if(as.character(df$ope[i]) != "acc") {
    while(flag) {
      if(as.character(df$ope[r]) == "acc" & r <= 626 & r >= 1) {
        acc <- acc + df$arg[r]
        flag <- is.na(df$ipa[r + 1])
        df$ipa[r + 1] <- r
        r <- r + 1
        }
      else if(as.character(df$ope[r]) == "jmp" & r + df$arg[r] <= 626 & r + df$arg[r] >= 1) {
        flag <- is.na(df$ipa[r + df$arg[r]])
        df$ipa[r + df$arg[r]] <- r
        r <- r + df$arg[r]
        }
      else if(as.character(df$ope[r]) == "nop" & r <= 626 & r >= 1) {
        flag <- is.na(df$ipa[r + 1])
        df$ipa[r + 1] <- r
        r <- r + 1
      }
    
      if(r == 626) {
        breakFlag <- TRUE
        break
        }
    }
  }
  if(breakFlag)
    break
}

acc

[1] 1033