算法练习--二分搜索哈希表-JS 实现

标签：

1. 以哈希KEY的值建立二叉哈希表

2. 根据传入的哈希值使用二分法搜索

具体实现如下：

function binarySearchTable(comp){
this.comp = comp;
this.kv = new Array();
}

binarySearchTable.prototype.add = function(k,v){
if(this.kv.length == 0 || this.comp(this.kv[0].key,k) >= 0){

this.kv.splice(0,0,{key:k,value:v});
return this;
}
else if(this.comp(this.kv[this.kv.length - 1].key,k) <= 0){
this.kv.push({key:k,value:v});
return this;
}
else{
for(var i = 1,j = i+1;j < this.kv.length; i ++, j++){
if((this.comp(this.kv[i].key) < 0 || this.comp(this.kv[i].key) == 0) && 
(this.comp(this.kv[j].key) > 0 || this.comp(this.kv[j].key) == 0)){
this.kv.splice(i,0,new {key:k,value:v});
return this;
}

}
}

};

binarySearchTable.prototype.getIndexByKey = function(k){
var lo = 0;
var hi = this.kv.length - 1;
var mid = (lo + hi) / 2 | 0;
var c = 0;
while(lo < hi && (++c) < 10){

if(this.comp(k,this.kv[mid].key) == 0){return mid;}
else if(this.comp(k,this.kv[lo].key) == 0){return lo;}
else if(this.comp(k,this.kv[hi].key) == 0){return hi;}
else if(this.comp(this.kv[mid].key,k) < 0){lo = mid;mid = (hi+lo) / 2 | 0;}
else {hi=mid;mid = (lo+hi)/2 | 0;}
}

return null;
};

binarySearchTable.prototype.removeByKey = function(k){
var index = this.getIndexByKey(k);
if(index != null){this.kv.splice(index,1);}
}

var comp = function(k1,k2){return k1 < k2 ? -1 : k1 == k2 ? 0 : 1;};
var tbl = new binarySearchTable(comp);
tbl.add("bec",1);
tbl.add("acd",1);
tbl.add("abc",1);
tbl.add("dec",1);
console.log(tbl.getIndexByKey("abc"));

tbl.removeByKey("abc");
console.log(tbl.getIndexByKey("abc"));

算法练习--二分搜索哈希表-JS 实现

标签：

原文地址：http://blog.csdn.net/lan_liang/article/details/42112793