/*
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* Copyright 2012 ZXing authors
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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@class ZXGenericGFPoly;
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/**
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* This class contains utility methods for performing mathematical operations over
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* the Galois Fields. Operations use a given primitive polynomial in calculations.
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*
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* Throughout this package, elements of the GF are represented as an int
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* for convenience and speed (but at the cost of memory).
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*/
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@interface ZXGenericGF : NSObject
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@property (nonatomic, strong, readonly) ZXGenericGFPoly *zero;
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@property (nonatomic, strong, readonly) ZXGenericGFPoly *one;
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@property (nonatomic, assign, readonly) int32_t size;
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@property (nonatomic, assign, readonly) int32_t generatorBase;
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+ (ZXGenericGF *)AztecData12;
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+ (ZXGenericGF *)AztecData10;
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+ (ZXGenericGF *)AztecData6;
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+ (ZXGenericGF *)AztecParam;
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+ (ZXGenericGF *)QrCodeField256;
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+ (ZXGenericGF *)DataMatrixField256;
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+ (ZXGenericGF *)AztecData8;
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+ (ZXGenericGF *)MaxiCodeField64;
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/**
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* Create a representation of GF(size) using the given primitive polynomial.
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*
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* @param primitive irreducible polynomial whose coefficients are represented by
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* the bits of an int, where the least-significant bit represents the constant
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* coefficient
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* @param size the size of the field
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* @param b the factor b in the generator polynomial can be 0- or 1-based
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* (g(x) = (x+a^b)(x+a^(b+1))...(x+a^(b+2t-1))).
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* In most cases it should be 1, but for QR code it is 0.
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*/
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- (id)initWithPrimitive:(int)primitive size:(int)size b:(int)b;
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/**
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* @return the monomial representing coefficient * x^degree
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*/
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- (ZXGenericGFPoly *)buildMonomial:(int)degree coefficient:(int)coefficient;
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/**
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* Implements both addition and subtraction -- they are the same in GF(size).
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*
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* @return sum/difference of a and b
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*/
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+ (int32_t)addOrSubtract:(int32_t)a b:(int32_t)b;
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/**
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* @return 2 to the power of a in GF(size)
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*/
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- (int32_t)exp:(int)a;
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/**
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* @return base 2 log of a in GF(size)
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*/
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- (int32_t)log:(int)a;
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/**
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* @return multiplicative inverse of a
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*/
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- (int32_t)inverse:(int)a;
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/**
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* @return product of a and b in GF(size)
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*/
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- (int32_t)multiply:(int)a b:(int)b;
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@end
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