AOC2504 ;; 2025 Day 4

T1  ;;TEST DATA 1;;
    ;..@@.@@@@.
    ;@@@.@.@.@@
    ;@@@@@.@.@@
    ;@.@@@@..@.
    ;@@.@@@@.@@
    ;.@@@@@@@.@
    ;.@.@.@.@@@
    ;@.@@@.@@@@
    ;.@@@@@@@@.
    ;@.@.@@@.@.
    ;;ENDS;;

DOIT(dataset,task,debug)
    N data,tsStart
    S debug=+$G(debug),task=$S(task=2:2,1:1) 
    I dataset=1 D LOAD^AOCBASE(2025,4,.data)
    I dataset=0 D LOADTD^AOCBASE("T1",$T(+0),.data)
    N resall S resall=0
    D TIMER^AOCBASE("START")
    I task=1 S resall=$$TASK1(task,.data,debug)
    I task=2 S resall=$$TASK2(task,.data,debug)
    D TIMER^AOCBASE("STOP")
    W "Answer is "_resall,!
    Q

TASK1(task,data,debug)
    N x,y,rollNo,res S res=0
    F y=1:1:data D          ;y = each line
    .F x=1:1:$L(data(y)) D  ;x = each char in line
    ..Q:$E(data(y),x)'="@"
    ..N total
    ..S total=$$EVALBARRIER(y,x)
    ..I total'<4 Q
    ..S res=res+1
    ..I task=2 S history(iterCount,res)=y_"`"_x
    W:debug "Task 1 Iteration: "_+$G(iterCount)_" Count: "_res,!
    Q res

TASK2(task,data,debug)
    N tres,iterCount,history
    S (iterCount,done,tres)=0
    F  Q:done  D
    .S iterCount=iterCount+1
    .W:debug "Iteration Count:"_iterCount,!
    .N iterRes S iterRes=$$TASK1(task,.data,debug)
    .I iterRes=0 S done=1 W:debug "Result of pass was 0",! Q
    .N roll S roll="" F  S roll=$O(history(iterCount,roll)) Q:roll=""  D
    ..N x,y 
    ..S y=$P(history(iterCount,roll),"`",1)    
    ..S x=$P(history(iterCount,roll),"`",2)    
    ..S $E(data(y),x)="."
    ..W:debug " * Marking y="_y_" x="_x_" as removed",!
    .I debug=2 ZW data B ;Used to check the pattern
    .S tres=tres+iterRes
    Q tres


EVALBARRIER(y,x)
    N barriers S barriers=0
    F dir="N","NE","E","SE","S","SW","W","NW" D
    .N y1,x1 S y1=y,x1=x
    .I dir["N" S y1=y1-1,x1=x1 Q:(y1=0)
    .I dir["S" S y1=y1+1,x1=x1 Q:(y1>data)
    .I dir["W" S y1=y1,x1=x1-1 Q:(x1=0)
    .I dir["E" S y1=y1,x1=x1+1 Q:(x1>$L(data(y)))
    .I $E(data(y1),x1)="@" S barriers=barriers+1
    Q barriers