Node.js examples for Data Structure:Vector
Vector class with constructor
if(!Array.prototype.equals) {
Array.prototype.equals = function (array) {
// if the other array is a falsy value, return
//// w w w. j av a 2s . c o m
if (!array) {
return false;
}
// compare lengths - can save a lot of time
//
if (this.length != array.length) {
return false;
}
for (var i = 0, l = this.length; i < l; i++) {
// Check if we have nested arrays
//
if (this[i] instanceof Array && array[i] instanceof Array) {
// recurse into the nested arrays
//
if (!this[i].equals(array[i])) {
return false;
}
}
else if (this[i] != array[i]) {
// Warning - two different object instances will never be equal: {x:20} != {x:20}
//
return false;
}
}
return true;
};
// Hide method from for-in loops
//
Object.defineProperty(Array.prototype, "equals", {enumerable: false});
}
var Vector = function(initialCapacity, maxCapacity) {
this.storage = [];
this.capacity = initialCapacity || 8; // Default array size initially to 8 elements
this.max = maxCapacity || 1 << 5; // Default max vector size to 32
this.length = 0;
};
Vector.prototype.insert = function(index, value) {
this.storage.splice(index, 0, value);
};
Vector.prototype.add = function(value) {
this.storage[this.length++] = value;
};
Vector.prototype.remove = function(index) {
if (index === undefined || index === null) {
delete this.storage[this.length];
}
else {
this.storage.splice(index, 1);
}
};
Vector.prototype.get = function(index) {
return this.storage[index];
};
Vector.prototype.set = function(index, value) {
this.storage[index] = value;
};
Vector.prototype.resize = function() {
this.capacity *= 2;
var tempStorage = new Array(this.capacity);
for (var i=0; i<this.storage.length; i++) {
tempStorage[i] = this.storage[i];
}
this.storage = tempStorage;
};
Vector.prototype.toArray = function() {
var result = [];
for (var i=0; i<this.length; i++) {
result[i] = this.storage[i];
}
return result;
};
var v = new Vector();
console.log("Initialize");
console.log(" v.length should be 0: " + (v.length === 0));
console.log(" v.capacity should be 8: " + (v.capacity === 8));
console.log(" v.max should be 32: " + (v.max === 32));
console.log(" v.storage should be []: " + (v.storage.equals([])));
console.log("Add 3");
v.add(0);
v.add(1);
v.add(2);
console.log(" v.length should be 3: " + (v.length === 3));
console.log(" v.toArray() should be [0, 1, 2]: " + (v.toArray().equals([0, 1, 2])));
console.log("Add 2 more");
v.add(3);
v.add(4);
console.log(" v.length should be 5: " + (v.length === 5));
console.log(" v.toArray() should be [0, 1, 2, 3, 4]: " + (v.toArray().equals([0, 1, 2, 3, 4])));
console.log("Insert 1 at v[3]");
v.insert(3, 2.5);
console.log(" v.length should be 6: " + (v.length === 6));
console.log(" v.toArray() should be [0, 1, 2, 2.5, 3, 4]: " + (v.toArray().equals([0, 1, 2, 2.5, 3, 4])));
console.log("Remove v[3]");
v.remove(3);
console.log(" v.length should be 5: " + (v.length === 5));
console.log(" v.toArray() should be [0, 1, 2, 3, 4]: " + (v.toArray().equals([0, 1, 2, 3, 4])));
console.log("Set v[2] = 15");
v.set(2, 15);
console.log(" v.get(2) should be 15: " + (v.get(2) === 15));
console.log("Add 4 more");
v.add(5);
v.add(6);
v.add(7);
v.add(8);
console.log(" v.length should be 9: " + (v.length === 9));
console.log(" v.capacity should be 16: " + (v.capacity === 16));
console.log("Remove from the end");
v.remove();
console.log(" v.toArray() should be [0, 1, 15, 3, 4, 5, 6, 7]: " + (v.toArray().equals([0, 1, 15, 3, 4, 5, 6, 7])));
console.log("Remove v[2]");
v.remove(2);
console.log(" v.toArray() should be [0, 1, 3, 4, 5, 6, 7]: " + (v.toArray().equals([0, 1, 3, 4, 5, 6, 7])));
console.log("Remove the first");
v.remove(0);
console.log(" v.toArray() should be [1, 3, 4, 5, 6, 7]: " + (v.toArray().equals([1, 3, 4, 5, 6, 7])));
console.log(" v.length should be 6: " + (v.length === 6));
console.log(" v.capacity should be 16: " + (v.capacity === 16));
console.log("Remove all but 2");
v.remove();
v.remove();
v.remove();
v.remove();
console.log(" v.toArray() should be [1, 3]: " + (v.toArray().equals([1, 3])));
console.log(" v.length should be 2: " + (v.length === 2));
console.log(" v.capacity should be 8: " + (v.capacity === 8));