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nighcanighca
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realize myers' algorithm
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‎lib/myers-compare.js

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Original file line numberDiff line numberDiff line change
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(function(global, undefined){
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var compare = function(cnt1, cnt2, splitter){
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var SPLITTER = splitter || '',
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MARK_EMPTY = -1,
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MARK_SAME = 0,
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STEP_NOCHANGE = 0,
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STEP_REPLACE = 1,
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STEP_REMOVE = 2,
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STEP_INSERT = 3;
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// result object
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var diff = [],
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result = {
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splitter: SPLITTER,
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diff: diff
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};
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// if string equal
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if(cnt1 === cnt2){
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return result;
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}
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// convert string to array
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var arr1 = cnt1.split(SPLITTER),
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arr2 = cnt2.split(SPLITTER);
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var N = arr1.length,
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M = arr2.length,
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MAX = N + M,
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steps = Array.apply(null, {length: M+N+1}).map(function(){return [];}),
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furthestReaching = [],
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dist = -1;
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furthestReaching[MAX + 1] = 0;
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// caculate min distance & log each step
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for(var D = 0; D <= MAX && dist === -1; D++){
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for(var k = -D, x, y, step; k <= D && dist === -1; k+=2){
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if(k === -D || (k !== D && furthestReaching[k - 1 + MAX] < furthestReaching[k + 1 + MAX])){
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x = furthestReaching[k + 1 + MAX];
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step = STEP_INSERT;
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}else{
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x = furthestReaching[k - 1 + MAX] + 1;
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step = STEP_REMOVE;
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}
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y = x - k;
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steps[x][y] = step;
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while(x < N && y < M && arr1[x] === arr2[y]){
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x++;
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y++;
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steps[x][y] = STEP_NOCHANGE;
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}
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furthestReaching[k + MAX] = x;
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if(x >= N && y >= M){
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dist = D;
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}
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}
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}
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// get contrast arrays (src & target) by analyze step by step
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var src = [], target = [];
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for(var i = N,j = M; i > 0 || j > 0;){
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switch(steps[i][j]){
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case STEP_NOCHANGE:
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src.unshift(arr1[i-1]);
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target.unshift(MARK_SAME);
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i -= 1;
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j -= 1;
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break;
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case STEP_REPLACE:
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src.unshift(arr1[i-1]);
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target.unshift(arr2[j-1]);
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i -= 1;
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j -= 1;
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break;
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case STEP_REMOVE:
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src.unshift(arr1[i-1]);
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target.unshift(MARK_EMPTY);
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i -= 1;
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j -= 0;
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break;
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case STEP_INSERT:
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src.unshift(MARK_EMPTY);
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target.unshift(arr2[j-1]);
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i -= 0;
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j -= 1;
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break;
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}
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}
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// convert contrast arrays to diff array
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var l = target.length,
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start, len, to,
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notEmpty = function(s){return s !== MARK_EMPTY;};
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for(i = l - 1; i >= 0;){
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// join continuous diffs
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for(j = i; target[j] !== MARK_SAME && j >= 0; j--){}
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if(j < i){
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start = src.slice(0, j + 1).filter(notEmpty).length; // start pos of diffs (on src)
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len = src.slice(j + 1, i + 1).filter(notEmpty).length; // length should be replaced (on src)
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to = target.slice(j + 1, i + 1).filter(notEmpty).join(SPLITTER);// new content
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diff.unshift([start, len, to]);
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}
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i = j - 1;
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}
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return result;
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};
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if(typeof module === "object" && typeof module.exports === "object"){
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module.exports = compare;
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}else{
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global.compare = compare;
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}
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})(this);

‎test/test.html

Lines changed: 13 additions & 1 deletion
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@@ -18,10 +18,13 @@
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<textarea id="in2">
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if(i===0){for(e in t.par){t.pars.push([e,t.par[e]].join("="))}}else{for(e=0;e<i;e++){r=t.filter[e];t.pars.push([r,t.par[r]].join("="))}}t.pars=t.pars.join("&");window.jsQa=new Image(1,1);jsQa.src=t.url+t.pars;t.cookieSet(t.flag,t.hash(t.pars),0,"/",lib.SITE_DOMAIN);t.callback()}catch(o){return""}}};(function(){var t=new lib.action.Qa;try{t.init({url:window.location.protocol+"//msg.iqiyi.com/jpb.gif"})}catch(e){}})();(function(){var t=new lib.action.Qa;var e=t.cookieGet("QC001")=="1";var i=t.cookieGet("QC005");var r;if(e||!i||window.location.protocol=="https:"||lib.SITE_DOMAIN.match(/pps/)){return}t.cookieSet("QC001","1",2xxx4,"/",lib.SITE_DOMAIN);var o="324";var n={qiyi_cookie:i};var a={sid:i,p:"iqiyi"};var s="http://nsclick.baidu.com/v.gif",c=[],h="BD_QIYI_LOG_"+(new Date).getTime(),f=window[h]=new Image;c.push("pid="+o);for(r in n){c.push(r+"="+encodeURIComponent(n[r]))}f.src=s+"?"+c.join("&")+"&t="+(new Date).getTime();var u="http://cpro.baidu.com/cpro/ui/html/sync.htm",l=[],d="BD_QIYI_LOG_"+(new Date).getTime(),p=window[d]=new Image;for(r in a){l.push(r+"="+encodeURIComponent(a[r]))}p.src=u+"?"+l.join("&")+"&t="+(new Date).getTime()})();(function(){var t=function(){var t=2;var e=window.location.hostname.split(".");e=e.slice(e.length-t);return e.join(".")}();var e=t.match(/pps/);var i="http://msg.iqiyi.com/b?t=20&p=10&p1=101"+("&pf="+(e?"20":"")+"1");var r=function(t,e){t=t||{};if(e.indexOf("?")==-1){e+="?"}else{e+="&"}var i=+new Date;t._=i;for(var r in t){if(t.hasOwnProperty(r)){e+=encodeURIComponent(r)+"="+encodeURIComponent(t[r])+"&"}}if(e[e.length-1]==="&"){e=e.slice(0,-1)}var n=new Image;n.src=e};function n(){var t=[];var e="block-";var i,r,n,o;var a="A".charCodeAt();var s=function(t){return document.getElementById(t)};var c=String.fromCharCode;var u;for(u=0;u<26;u++){i=c(a+u);n=e+i;o=s(n);if(o){o["__bid__"]=i;t.push(o)}}for(u=0;u<26;u++){r=c(a+u);var h=false;for(var f=0;f<26;f++){i=c(a+f);n=e+r+i;o=s(n);if(o){h=true;o["__bid__"]=r+i;t.push(o)}}if(!h){break}}return t}function o(){var t=[];var e="block-";var i=document.getElementsByTagName("qchunk"),r,n;for(var o=0,a=i.length;o<a;o++){r=i[o];n=r.id||"";if(n.substr(0,e.length).toLowerCase()==e){r["__bid__"]=n.substr(exxx.length);t.push(r)}}return t}var a=function(t){t=t||window.event;var e=t.target||t.srcElement;var n=document.documentElement&&document.documentElement.scrollTop||document.body.scrollTop;var o=document.documentElement&&document.documentElement.scrollLeft||document.body.scrollLeft;var a=document.documentElement&&document.documentElement.scrollWidth||document.body.scrollWidth;var s=document.documentElement&&document.documentElement.scrollHeight||document.body.scrollHeight;var c=document.documentElement&&document.documentElement.clientHeight||document.body.clientHeight;var u=document.documentElement&&document.documentElement.clientWidth||document.body.clientWidth;var h=Math.max(s,c);var f=Math.max(a,u);var l=this["__bid__"]||"";var d=g(this.getAttribute("data-pb"),"&");var pxxx,m,v;do{p=e;m=p.getAttribute("rseat");v=p.tagName.toUpperCase();e=e.parentNode;if(p==this){break}}while(!m&&v!=="A"&&v!=="IMG");var _=g(p.getAttribute("data-pb"),"&");var b,I,y;if(m){_.rseat=m}if(v==="A"){b=p.title||"";I="a";y=p.getAttribute("href")||""}else if(v==="IMG"){b=p.alt||"";I="i";y=""}else{b=p.title||"";I="e";y=""}var k,C,E;E=g(document.cookie,";");k=E["P00003"]||"";C=E["QC005"]||E["QC006"]||"";var M={block:l,rt:I,r:b,rlink:y,pu:decodeURIComponent(k),u:decodeURIComponent(C),re:f+"*"+h,clkx:t.clientX+o,clky:t.clientY+n};r(w(M,d,_),i)};var s=n();var c=o();var u,h;for(var f=0,l=s.length;f<l;f++){if(c.indexOf(s[f])==-1){c.push(s[f])}}if(c.length===0){u=document.getElementsByTagName("boxxxdy")[0];h=a.bind(u);if(u.addEventListener){u.addEventListener("mousedown",h,false)}else{u.attachEvent("onmousedown",h)}}else{for(var d=0,p=c.length;d<p;d++){var m=c[d];var v=a.bind(m);if(m.addEventListener){m.addEventListener("mousedown",v,false)}else{m.attachEvent("onmousedown",v)}}}function g(t,e){var i={};e=e||"&";if(t){var r=t.split(e),n;for(var o=0,a=r.length;o<a;o++){n=r[o];if(n){n=n.split(/\s*=\s*/g);if(n[0]){i[n[0].replace(/^\s*|\s*$/g,"")]=n[1]||""}}}}return i}function w(t,e){var i=t||{};var r;for(var n=1,o=arguments.length;n<o;n++){r=arguments[n];if(r){for(var a in r){if(r.hasOwnProperty(a)){i[a]=r[a]}}}}return i}})();</textarea>
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<script type="text/javascript" src="../lib/compare.js"></script>
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<!-- <script type="text/javascript" src="../lib/compare.js"></script> -->
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<script type="text/javascript" src="../lib/myers-compare.js"></script>
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<script type="text/javascript" src="../lib/merge.js"></script>
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<script type="text/javascript">
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var test = function(s1, s2, splitter){
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//console.log(s1, s2);
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var t = Date.now();
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var compareResult = compare(s1, s2, splitter);
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}
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};
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/*
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// do random tests
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for(var l = 1000; l > 0; l--){
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test((Math.random() + '').slice(-l), (Math.random() + '').slice(-l));
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}
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console.info('FINISHED');
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*/
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// do test with given input
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var in1 = document.getElementById('in1'),
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in2 = document.getElementById('in2');
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