No Four in a Row

"NoFourinaRow"isanentertainingpuzzle.Despitetheonlysimplerule,somelevelsareverydifficulttosolve.Solvingthispuzzlerequiresalotofattention.TosolvethepuzzleyouneedtofillALLthecellsoftheplayingfieldwithonlytwocharacters:"X"and"O".Theonlyrule-horizontally,verticallyordiagonallythereshouldnotbefouridenticalsymbols.Ifintheprocessofsolvingapuzzle,anapplicationwillnoticesuchasituation,itwillindicatetoyoubyhighlightingthecorrespondingcharacters.Eachlevelhasonlyone,uniquesolution.Eachlevelcanbecompletedguidedonlybysimplelogicalsolutions,withoutguessing.Inourapplication,wehavecreated6000uniquelevelswithvaryingdegreesofdifficulty.Ifthisisyourfirsttimeplayingthisgame,trytheNovicelevel.Eachdifficultylevelcontains1000uniquelevels.Wherelevel1iseasiestand1000isthemostdifficult.Ifyoucaneasilysolvethe1000thlevel,trythefirstlevelofthenextlevelofdifficulty.Goodluck!