JavaScript - Searching Algorithms(sequential search, last occurence)

Data Structures and Algorithms With Javascript
(O'Reilly Media)
Michael McMillan(著)

開発環境

• OS X El Capitan - Apple (OS)
• Emacs (Text Editor)
• JavaScript (プログラミング言語)
• SpiderMonkey, Node.js(V8) (JavaScript engine)

Data Structures and Algorithms With Javascript (Michael McMillan(著)、O'Reilly Media)のChapter 13(Searching Algorithms)、Exercises 1.(No. 6070)を解いてみる。

Exercises 1.(No. 6070)

JavaScript(Emacs)

/*jslint         browser : true, continue : true,
  devel  : true, indent  : 4,    maxerr   : 50,
  newcap : true, nomen   : true, plusplus : false,
  regexp : true, sloppy  : true, vars     : false,
  white  : true
*/

/*global */
var nums = [],
    i,
    num = 23,
    len = 1000000,
    start,
    stop;    

Array.prototype.dispArr = function () {
    var i,
        max,
        str = '';

    for (i = 0, max = this.length; i < max; i += 1) {
        str += this[i] + ' ';
        if (i % 10 === 9) {
            str += '\n';
        }
    }
    if (i % 10 !== 0) {
        str += '\n';
    }
    console.log(str);
};
Array.prototype.seqSearch = function (data) {
    var i,
        len = this.length;

    for (i = len - 1; i >= 0; i -= 1) {
        if (this[i] === data) {
            return true;
        }
    }
    return false;
};

for (i = 0; i < len; i += 1) {
    nums[i] = 0;
}

nums.push(num);
start = new Date().getTime();
nums.seqSearch(num);
stop = new Date().getTime();
console.log(stop - start);

nums.pop();

nums.shift(num);
start = new Date().getTime();
nums.seqSearch(num);
stop = new Date().getTime();
console.log(stop - start);

出力結果(Terminal, shell, SpiderMonkey)

$ jslint sample1.js

sample1.js is OK.
$ node sample1.js
1
16
$