public void drawDiamond(int num){
        char[][] b = new char[num][num];
        if(oddNumber(num)){
            for(int i = 0;i <= num-1;i++){
                for(int j = 0;j <= num-1;j++){
                    if((i + j == num/2 )||(i + j == num + 1)||(i - j == num/2)||(j - i == num/2) ){
                        b[i][j] = '*';
                    }else{
                        b[i][j] = ' ';
                    }
                }
            }
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