/*** 散列表碰撞处理、开链法、HashTable散列。* 将数组里的元素位置，也设置为数组，当两个数据的散列在同一个位置时，* 就可以放在这个位置的二维数组里，解决了散列函数的碰撞处理问题*/
function HashTable() {this.table = new Array(137);this.betterHash = betterHash;//散列函数this.showDistro = showDistro;//显示散列表里的数据this.buildChains = buildChains;//生成二维数组this.put = put;//将数据存储到散列表this.get = get;//从散列表中取出某个数据
}// put for separate chaining
function put(key, data) {var pos = this.betterHash(key);var index = 0;if (this.table[pos][index] == undefined) {this.table[pos][index] = data;}else {while (this.table[pos][index] != undefined) {++index;}this.table[pos][index] = data;}
}/*散列函数*/
function betterHash(string) {const H = 37;var total = 0;for (var i = 0; i < string.length; ++i) {total += H * total + string.charCodeAt(i);}total = total % this.table.length;if (total < 0) {total += this.table.length-1;}return parseInt(total);
}function showDistro() {var n = 0;for (var i = 0; i < this.table.length; ++i) {if (this.table[i][n] != undefined) {console.log(i + ": " + this.table[i]);}}
}function buildChains() {for (var i = 0; i < this.table.length; ++i) {this.table[i] = new Array();}
}// get for separate chaining
function get(key) {var index = 0;var pos = this.betterHash(key);while ((this.table[pos][index] != undefined)&&(this.table[pos][index] != key)) {index += 1;}if(this.table[pos][index] == key) {console.log(key+" 的键值为： "+this.table[pos][index]);return this.table[pos][index];}else{console.log("无该键值");return undefined;}}/*测试开链法*/
var someNames = ["David", "Jennifer", "Donnie", "Raymond","Cynthia", "Mike", "Clayton", "Danny", "Jonathan"];
var hTable = new HashTable();
hTable.buildChains();
for (var i = 0; i < someNames.length; ++i) {hTable.put(someNames[i],someNames[i]);
}
hTable.showDistro();
hTable.betterHash("Jennifer");
hTable.get("Jennidfer");
hTable.get("Jennifer");