The purpose of this algorithm is to tell if a given pattern is found in a list of patterns. In this example, we're trying to find the pattern [2,3,6] in a "commands" array. This algorithm uses a threshold value to ignore certain patterns.

find_pattern.js

(function(){
	var threshold = 6;
	var service = {
		isCommandEntered: function isCommandEntered(commands, commandToFind){
		 	return commands.map(function(value, index, self){
		 		var n=1;
		 		while(self[++index]===value) ++n;
		 		return {command: value, weight: n};
		 	})
		 	.filter(function(value, index, self){
		 		return !(self[index-1] && (self[index-1].command===self[index].command)) && value.weight <= threshold;
		 	})
		 	.map(function(value, index, self){
		 		return value.command;
		 	})
		 	.join('').indexOf(commandToFind.join('')) >= 0;
		}
	};
	
	// the pattern to find in a given command-list
	var commandToFind = [2,3,6];
	var commands = [];
	
	// cas 1: empty command-list
	console.log(service.isCommandEntered(commands, commandToFind));
	
	// cas 2: valid command-list
	commands = [1,1,2,2,2,2,3,6,6];
	console.log(service.isCommandEntered(commands, commandToFind));
	
	// cas 3: valid command-list containing a non-valid sub-command
	commands = [1,1,2,2,2,2,3,6,6,1,1,1,1,1,1,1,1];
	console.log(service.isCommandEntered(commands, commandToFind));
	
	
	// cas 4: valid command-list
	commands = [4,4,4,4,4,4,4,1,1,2,2,2,2,3,6,6];
	console.log(service.isCommandEntered(commands, commandToFind));
	
	
	// cas 4: valid command-list
	commands = [4,4,4,4,4,4,4,1,1,1,1,1,1,1,2,2,2,2,3,6,6,1,1,1,1];
	console.log(service.isCommandEntered(commands, commandToFind));
	
	
	// cas 4: non-valid command-list
	commands = [4,4,4,4,4,4,4,1,1,1,1,1,1,1,2,2,2,2,2,2,2,2,3,6,6,1,1];
	console.log(service.isCommandEntered(commands, commandToFind));
})();