I dont even remember what this is about - euler problem #11 incorrect solution - node js

euler11.js

      
/* ZaidaZadkiel at march 28, 2020 
   euler problem #11 - incorrect 
   
   run video at
   https://www.youtube.com/watch?v=VMW04nEtKEk
*/
 
big =[
08,02,22,97,38,15,00,40,00,75,04,05,07,78,52,12,50,77,91,08,
49,49,99,40,17,81,18,57,60,87,17,40,98,43,69,48,04,56,62,00,
81,49,31,73,55,79,14,29,93,71,40,67,53,88,30,03,49,13,36,65,
52,70,95,23,04,60,11,42,69,24,68,56,01,32,56,71,37,02,36,91,
22,31,16,71,51,67,63,89,41,92,36,54,22,40,40,28,66,33,13,80,
24,47,32,60,99,03,45,02,44,75,33,53,78,36,84,20,35,17,12,50,
32,98,81,28,64,23,67,10,26,38,40,67,59,54,70,66,18,38,64,70,
67,26,20,68,02,62,12,20,95,63,94,39,63,08,40,91,66,49,94,21,
24,55,58,05,66,73,99,26,97,17,78,78,96,83,14,88,34,89,63,72,
21,36,23,09,75,00,76,44,20,45,35,14,00,61,33,97,34,31,33,95,
78,17,53,28,22,75,31,67,15,94,03,80,04,62,16,14,09,53,56,92,
16,39,05,42,96,35,31,47,55,58,88,24,00,17,54,24,36,29,85,57,
86,56,00,48,35,71,89,07,05,44,44,37,44,60,21,58,51,54,17,58,
19,80,81,68,05,94,47,69,28,73,92,13,86,52,17,77,04,89,55,40,
04,52,08,83,97,35,99,16,07,97,57,32,16,26,26,79,33,27,98,66,
88,36,68,87,57,62,20,72,03,46,33,67,46,55,12,32,63,93,53,69,
04,42,16,73,38,25,39,11,24,94,72,18,08,46,29,32,40,62,76,36,
20,69,36,41,72,30,23,88,34,62,99,69,82,67,59,85,74,04,36,16,
20,73,35,29,78,31,90,01,74,31,49,71,48,86,81,16,23,57,05,54,
01,70,54,71,83,51,54,69,16,92,33,48,61,43,52,01,89,19,67,48];
 
 
// its a grid, find the diagonal (4x4) which gets the higher sum
var biggest = 0;
var cell1, cell2, cell3, cell4;
var last;
 
function diagonaldown(startindex){
  r = big[startindex   ] *
      big[startindex+21] *
      big[startindex+42] * 
      big[startindex+63]
 
  cell1   = startindex;
  cell2   = startindex+21;
  cell3   = startindex+42;
  cell4   = startindex+63;
  last    = r;
  biggest = r > biggest ? r : biggest;
  return startindex
}
 
function diagonalup(startindex) {
  r = big[startindex   ] *
      big[startindex-19] *
      big[startindex-38] * 
      big[startindex-57]
 
  cell1   = startindex;
  cell2   = startindex-19;
  cell3   = startindex-38;
  cell4   = startindex-57;
  last    = r;
  biggest = r > biggest ? r : biggest; 
  return startindex;
}
 
function linehoriz(startindex){
  r = big[startindex  ] *
      big[startindex+1] *
      big[startindex+2] * 
      big[startindex+3] 
 
  cell1   = startindex;
  cell2   = startindex+1;
  cell3   = startindex+2;
  cell4   = startindex+3;
  last    = r;biggest = r > biggest ? r : biggest;
  return startindex;
}
 
function linevert (startindex) {
  r = big[startindex   ] *
      big[startindex+20] *
      big[startindex+40] * 
      big[startindex+60] 
  
  cell1   = startindex;
  cell2   = startindex+20;
  cell3   = startindex+40;
  cell4   = startindex+60;
  last    = r;  biggest = r > biggest ? r : biggest;
  return startindex;
}
 
function getindex(x, y) {
  return y * 20  + x
}
 
const syncWait = ms => {
    const end = Date.now() + ms
    while (Date.now() < end) continue
}
 
function debug(index){
  process.stdout.write('\u001b[2J\u001b[;H');    
 
  for(y = 0 ; y != 20 ; y++ ) {
    for(x = 0 ; x != 20 ; x++ ) {
      ch = y * 20 + x;
      highlight = (ch == cell1) || 
                  (ch == cell2) || 
                  (ch == cell3) || 
                  (ch == cell4) 
      n = big[ch]
      process.stdout.write(
        ( highlight ? "\u001b[33m*" : " ")  +
        ( n < 10 ? "0" + n : n) + 
        ( highlight ? "*\u001b[39m" : " ")  
      );
    }
    process.stdout.write('\n');
  }
  console.log(`x: ${index%20} y: ${(index/20)>>0}, product: ${last}`)
  console.log("biggest product: " + biggest);
  syncWait(200)
}
 
 
 
for( s = 0; s!=5; s++){
  for(i = 0; i != 17; i++) {
    debug( diagonaldown( getindex(i, s*4) ) )
  }
  for(i = 0; i != 17; i++) {
    debug( diagonalup(   getindex(s*4, i+3) ) )
  }
  for(i = 0; i != 20; i++) {
    debug( linevert    ( getindex(  i, s*4) ) )
  }
  for(i = 0; i != 20; i++) {
    debug( linehoriz   ( getindex(s*4,   i) ) )
  }
}
 
 
 
console.log("biggest number: " + biggest);