I working on the Sudoku puzzle, the following code works but it's easy to see that there is a lot of duplicated code. How can I optimize it? Thanks
Problem: getSection: This function should accept three arguments: a sudoku grid, and an x and y coordinate for one of the puzzle's 3x3 subgrids. The function should return an array with all the numbers in the specified subgrid.
Input example:
var puzzle = [[ 8,9,5, 7,4,2, 1,3,6 ],
[ 2,7,1, 9,6,3, 4,8,5 ],
[ 4,6,3, 5,8,1, 7,9,2 ],
[ 9,3,4, 6,1,7, 2,5,8 ],
[ 5,1,7, 2,3,8, 9,6,4 ],
[ 6,8,2, 4,5,9, 3,7,1 ],
[ 1,5,9, 8,7,4, 6,2,3 ],
[ 7,4,6, 3,2,5, 8,1,9 ],
[ 3,2,8, 1,9,6, 5,4,7 ]];
Output:
getSection(puzzle, 0, 0);
// -> [ 8,9,5,2,7,1,4,6,3 ]
Solution:
function getSection(arr, x, y) {
var section = [];
if (y === 0) {
arr = arr.slice(0, 3);
if (x === 0) {
arr.forEach(function (element) {
section.push(element.slice(0, 3));
})
} else if (x === 1) {
arr.forEach(function (element) {
section.push(element.slice(3, 6));
})
} else {
arr.forEach(function (element) {
section.push(element.slice(6, 9));
})
}
}
if (y === 1) {
arr = arr.slice(4, 7);
if (x === 0) {
arr.forEach(function (element) {
section.push(element.slice(0, 3));
})
} else if (x === 1) {
arr.forEach(function (element) {
section.push(element.slice(3, 6));
})
} else {
arr.forEach(function (element) {
section.push(element.slice(6, 9));
})
}
}
if (y === 2) {
arr = arr.slice(6, 9);
if (x === 0) {
arr.forEach(function (element) {
section.push(element.slice(0, 3));
})
} else if (x === 1) {
arr.forEach(function (element) {
section.push(element.slice(3, 6));
})
} else {
arr.forEach(function (element) {
section.push(elemet.slice(6, 9));
})
}
}
var subgrid = section.reduce(function (a, b) {
return a.concat(b);
},
[]
);
return subgrid;
}
console.log(getSection(puzzle, 0, 0));
// // -> [ 8,9,5,2,7,1,4,6,3 ]
console.log(getSection(puzzle, 1, 0));
// -> [ 7,4,2,9,6,3,5,8,1 ]
I assume your x and y will not exceed your array length. Here's the simplest way to achieve the solution.
function getSection(arr, x, y) {
var GRID_SIZE = 3;
var indexX = x*GRID_SIZE;
var indexY = y*GRID_SIZE;
var results = [];
for(var i = indexY; i< indexY+GRID_SIZE; i++){
results = results.concat(puzzle[i].slice(indexX, indexX+GRID_SIZE));
}
return results;
}
console.log(getSection(puzzle, 0, 0));
// // -> [ 8,9,5,2,7,1,4,6,3 ]
console.log(getSection(puzzle, 1, 0));
// -> [ 7,4,2,9,6,3,5,8,1 ]