Verification program for http://domino.research.ibm.com/Comm/wwwr_ponder.nsf/Challenges/December2012.html

n-grid.html

<script>
/*
var grid = [
							[0,0,0,0,0,0],
							[0,0,0,0,0,0],
							[0,0,0,0,0,0],
							[0,0,0,0,0,0],
							[0,0,0,0,0,0],
							[0,0,0,0,0,0]
					 ];
*/					 

var grid = [
							[3,1,2,3,1,3],
							[2,1,3,4,1,2],
							[4,1,4,2,1,4],
							[3,2,5,3,1,3],
							[1,4,1,5,4,2],
							[2,3,1,2,3,1]
					 ];

					 
console.log(sum(grid),verify(grid));

function verify(grid){
	var correct = true;

	for(var i=0; i<grid.length; i++){
		var curRow = grid[i];
		for(var j=0; j<curRow.length; j++){
			if(!satisfied(grid,i,j)){
				console.log("Error at ("+i+","+j+")");
				correct = false;
			}
		}
	}

	return correct;
}

function satisfied(grid, row, col){
	var neighbours = [];
	var val = grid[row][col];
	
	neighbours[getVal(grid, row-1, col)] = true;
	neighbours[getVal(grid, row+1, col)] = true;
	neighbours[getVal(grid, row, col-1)] = true;
	neighbours[getVal(grid, row, col+1)] = true;
	
	for(var i=1;i<val;i++){
		if(!neighbours[i]){
			return false;
		}
	}
	return true;
}

function getVal(grid, row, col){
	var row = grid[row]
	if(row){
		var val = row[col];
		if(val){
			return val;
		}
	}
	return 0;
}

function sum(grid){
	var sum = 0;

	for(var i=0; i<grid.length; i++){
		var curRow = grid[i];
		for(var j=0; j<curRow.length; j++){
			sum+=curRow[j];
		}
	}

	return sum;
}

</script>