c - Is i=i+1 an undefined behaviour? -


i'm using codeblocks , giving different output other compilers , can't find solution it.what's undefined behaviour in program , there solution avoid it?

this code print nth number in number system 3 & 4.

#include<stdio.h>                                                               #include<math.h>                                                                int main(void)                                                                  {                                                                                   int n,i,value;                                                                  scanf("%d",&n);                                                                 value=i=0;                                                                      while(n>0)                                                                      {                                                                                   if((n%2)==0)                                                                    {                                                                                   value+=4*pow(10,i);                                                         }                                                                               else                                                                            {                                                                                   value+=3*pow(10,i);                                                         }                                                                               n=(n-1)/2;                                                                      i=i+1;                                                                      } printf("\nthe number : %d",value);                                                                           }

it works fine numbers upto 6..and output numbers greater 6 1 less should be. e.g. if n=7,output=332 should 333.

edit : provided full code braces.

there no undefined behavior in code. i=i+1; well-defined behavior, not confused i=i++; gives undefined behavior.

the thing cause different outputs here floating point inaccuracy.

try value += 4 * (int)nearbyint(pow(10,i)); , see if makes difference.


Comments

Post a Comment

Popular posts from this blog

javascript - Google App Script ContentService downloadAsFile not working -

i have web app developed using google app script htmlservice , html form, populating excel sheet in google drive using spreadsheetapp . , 1 section calling contentservice download data excel file. function doget(e) { // read excel sheet //getappfile(); // render application html template return htmlservice.createtemplatefromfile('index').evaluate() .settitle('go smart') .setsandboxmode(htmlservice.sandboxmode.iframe); } function downloaddoublequatecsvfile() { var sheetid = propertiesservice.getscriptproperties().getproperty('sheetid'); var ss = spreadsheetapp.openbyid(sheetid).getactivesheet(); //var ss = spreadsheetapp.getactivespreadsheet().getactivesheet(); var maxcolumn = ss.getlastcolumn(); var maxrow = ss.getlastrow(); var data = ss.getrange(1, 1, maxrow, maxcolumn).getvalues(); if (data.length > 1) { var csv = ""; (var row = 0; row < data.length; row++) { (var c...
Read more

javascript - Function overwritting -

is there way overwrite function or event handling in function? using addeventlistener, can have many event handlers on element want var test=document.getelementbyid("div"); test.addeventlistener("click",function(){alert("im first");},false); test.addeventlistener("click",function(){alert("im second");},false); // alerts "im first" , after "im second" but if want overwrite function/event example based on client width example this function one() { alert("first"); } function two() { alert("second"); } window.onresize = function() { var test = document.getelementbyid("div"); if (window.innerwidth > 500) { test.onclick = 1 } else { test.onclick = two; } } is possible in javascript? in case use effective little known approach. addeventlistener can accept object property handleevent event handler. in case it's easy overwr...
Read more

c# - Exception when attempting to modify Dictionary -

i creating dictionary manage threads , ran exception when attempt clear dead threads after adding threads dictionary. using system; using system.collections.generic; using system.threading; namespace syscat { public class threadmanager { public static readonly threadmanager globalthreadmanager = new threadmanager( ); /// <summary> /// initializes new instance of <see cref="syscat.threadmanager"/> class. /// </summary> public threadmanager( ) { } /// <summary> /// create new threadmanager threads within basetm , deinitializes basetm /// </summary> public threadmanager( threadmanager basetm ) { this.threads = basetm.threads; basetm.threads.clear( ); } private dictionary<guid,thread> threads = new dictionary<guid, thread>( ); /// <summary> /// attempts obtain unused threadid within ...
Read more