JS implementation of Sudoku algorithm

Recently, we are going to develop Sudoku games with small programs, so we have studied the algorithms of the next Sudoku feasibility data. The specific code is as follows:

varChess//the state of all chess piecesvarChessstack = [];//Cache Point//Create a chessboardfunctioncreatchess () {Chess= [];  for(vari = 0; I < 9; i++) {Chess[i]= [];  for(varj = 0; J < 9; J + +) {Chess[i][j]= {num:0,fixed:false, temp:[1,2,3,4,5,6,7,8,9]}; }    }}//Print Boardfunctionprintchess () {varSay = "";  for(vari = 0; I < 9; i++)    {         for(varj = 0; J < 9; J + +) {say+=Chess[i][j].num; } Say+ = ' \ n '; } console.log (say);}//pre-set nine Gongge position numbers that don't affect each otherfunctionSetarea (A, b) {vartemp = [1,2,3,4,5,6,7,8,9];//Each small nine Gongge contains nine numbers     for(vari = A; I < b; i++)    {         for(varj = A; J < b; J + +)        {            varlen = temp.length;//the remaining length of temp            varindex = Getrandom (len);//randomly extract aChess[i][j].num = Temp[index];//Assign ValueChess[i][j].fixed =true;//Assign ValueTemp.splice (index,1);//Delete the assigned value        }    }}//set number to solvefunctionSetpre (r,c,v) {Chess[r][c]= {num:v,fixed:true, temp:[]};}//get a random number subscriptfunctionGetrandom (a) {returnMath.floor (Math.random () *a);}//Initialize the boardfunctionChessinit () { for(vari = 0; I < 9; i++)    {         for(varj = 0; J < 9; ) {            //when the number is determined, the next one is randomly taken.            if(!chess[i][j].fixed) {                varlen = chess[i][j].temp.length;//the remaining length of temp                //when there is an optional number                if(Len > 0)                {                    varindex = Getrandom (len);//randomly extract aChess[i][j].num = Chess[i][j].temp[index];//Assign ValueChess[i][j].temp.splice (index,1);//Delete the assigned valueChessstack.push ([I,j,json.parse (Json.stringify (chess))]);//StorageChess[i][j].fixed =true;//becomes OK                    if(!Checktempnum (I,J)) {                        varcs = Chessstack.pop ();//BACKSPACEi = Cs[0]; J= Cs[1]; Chess= Cs[2];//Remove Board Storage point                    }                }                Else                {                    //when there are no optional numbers.                    varcs = Chessstack.pop ();//BACKSPACEi = Cs[0]; J= Cs[1]; Chess= Cs[2];//Remove Board Storage point                }            }            Else{J++;//into a            }        }    }}//Delete a specific elementfunctionRemovebyvalue (r,c,v) {if(Chess[r][c].num = =v) {return false;//conflict.    }    if(chess[r][c].fixed) {return true;//has been determined, there is no need to delete    }    varLen =chess[r][c].temp.length;  for(vari = 0; i < Len; i++)    {        if(Chess[r][c].temp[i] = =v) {chess[r][c].temp.splice (I,1);//Remove Alternate numbers             Break;//Exit        }    }    returnChess[r][c].temp.length==0?false:true;//there is no certainty and there is no alternative element, then return error}//remove a number from the relevant 20-grid alternative listfunctionChecktempnum (r,c) {vari,j; varnum = Chess[r][c].num;//the number to remove    //Check Column     for(i = 0; i < 9; i++)    {        if(I! = R &&!removebyvalue (I,c,num))return false;//Remove alternative numbers and determine the legitimacy of the numbers    }    //Check Row     for(j = 0; J < 9; J + +)    {        if(J! = C &&!removebyvalue (R,j,num))return false;//Remove alternative numbers and determine the legitimacy of the numbers    }    //Check Small nine    varleft = Math.floor (R/3) *3;//the coordinates of the small ninevartop = Math.floor (C/3) *3;//draws the upper-left coordinate of the small nine for(i = left; i < left+3; i++)    {         for(j = top; J < Top+3; J + +)        {            if(i = = r && J = =c) {Continue;//The same lattice jumps over            }            if(!removebyvalue (I,j,num))return false;//Remove alternative numbers and determine the legitimacy of the numbers        }    }    return true;}//Initializefunctionchess () {creatchess ();//Create a chessboard    //Setarea (0,3);//random set upper left corner nine number    //Setarea (3,6);//randomly set the median nine lattice number    //Setarea (6,9);//randomly set the lower right corner of the nine numberSetpre (0,2,5); Setpre (0,3,3); Setpre (1,0,8); Setpre (1,7,2); Setpre (2,1,7); Setpre (2,4,1); Setpre (2,6,5); Setpre (3,0,4); Setpre (3,5,5); Setpre (3,6,3); Setpre (4,1,1); Setpre (4,4,7); Setpre (4,8,6); Setpre (5,2,3); Setpre (5,3,2); Setpre (5,7,8); Setpre (6,1,6); Setpre (6,3,5); Setpre (6,8,9); Setpre (7,2,4); Setpre (7,7,3); Setpre (8,5,9); Setpre (8,6,7); Chessinit ();//Initialize the boardPrintchess ();//Print Board}chess ();

JS implementation of Sudoku algorithm