const std = @import("std");
const warn = std.debug.warn;

pub fn main() anyerror!void{
    var arena = std.heap.ArenaAllocator.init(std.heap.page_allocator);
    defer arena.deinit();
    
    const allocator = &arena.allocator;

    //read data from file.
        //each line is one number
    var file = try std.fs.cwd().openFile("input1", .{});
    defer file.close();

    const file_size:u64 = try file.getEndPos();
    std.debug.print("{0} \n", .{file_size});
    
    var buffer = try allocator.alloc(u8, file_size);
    var reader = file.reader();
    
    var size = try reader.read(buffer);

    std.debug.print("{0} \n", .{buffer});

//read from buffer
//put value in array
//is value 10?
//finish array, interpret as int32.
const numberArr: []u32 = try allocator.alloc(u32, 4);
var i:i32 = 0;

for(buffer) |byte|{
    if(byte == 10){
        i=0;
        //std.debug.print("{0}", .{@as(i32,numberArr)});

    }else{
        //numberArr.push(byte);
    }
    i += 1;
}

    // for(buffer) |byte|{
    //     if(byte == 10){
    //         std.debug.print("Newline!\n", .{});
    //     }else{
    //         std.debug.print("{0}", .{byte});
    //     }
    // }
    



//what two numbers from the input file add up to 2020?
//once those two numbers have been found, multiply them


//naive:
//foreach number |num1|
//foreach number |num2|
//if(num1+num2 = 2020)
//return num1*num2

//v2
//foreach number |num1|
// if(number.contains(2020-num1))
//      return num1*(num2;
}