/*
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* Copyright 2008 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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import OneDReader from './OneDReader';
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import NotFoundException from '../NotFoundException';
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import FormatException from '../FormatException';
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/**
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* <p>Encapsulates functionality and implementation that is common to UPC and EAN families
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* of one-dimensional barcodes.</p>
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*
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* @author dswitkin@google.com (Daniel Switkin)
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* @author Sean Owen
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* @author alasdair@google.com (Alasdair Mackintosh)
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*/
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export default class AbstractUPCEANReader extends OneDReader {
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constructor() {
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super(...arguments);
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this.decodeRowStringBuffer = '';
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}
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// private final UPCEANExtensionSupport extensionReader;
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// private final EANManufacturerOrgSupport eanManSupport;
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/*
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protected UPCEANReader() {
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decodeRowStringBuffer = new StringBuilder(20);
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extensionReader = new UPCEANExtensionSupport();
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eanManSupport = new EANManufacturerOrgSupport();
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}
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*/
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static findStartGuardPattern(row) {
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let foundStart = false;
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let startRange;
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let nextStart = 0;
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let counters = Int32Array.from([0, 0, 0]);
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while (!foundStart) {
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counters = Int32Array.from([0, 0, 0]);
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startRange = AbstractUPCEANReader.findGuardPattern(row, nextStart, false, this.START_END_PATTERN, counters);
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let start = startRange[0];
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nextStart = startRange[1];
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let quietStart = start - (nextStart - start);
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if (quietStart >= 0) {
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foundStart = row.isRange(quietStart, start, false);
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}
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}
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return startRange;
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}
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static checkChecksum(s) {
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return AbstractUPCEANReader.checkStandardUPCEANChecksum(s);
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}
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static checkStandardUPCEANChecksum(s) {
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let length = s.length;
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if (length === 0)
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return false;
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let check = parseInt(s.charAt(length - 1), 10);
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return AbstractUPCEANReader.getStandardUPCEANChecksum(s.substring(0, length - 1)) === check;
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}
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static getStandardUPCEANChecksum(s) {
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let length = s.length;
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let sum = 0;
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for (let i = length - 1; i >= 0; i -= 2) {
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let digit = s.charAt(i).charCodeAt(0) - '0'.charCodeAt(0);
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if (digit < 0 || digit > 9) {
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throw new FormatException();
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}
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sum += digit;
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}
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sum *= 3;
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for (let i = length - 2; i >= 0; i -= 2) {
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let digit = s.charAt(i).charCodeAt(0) - '0'.charCodeAt(0);
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if (digit < 0 || digit > 9) {
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throw new FormatException();
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}
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sum += digit;
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}
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return (1000 - sum) % 10;
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}
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static decodeEnd(row, endStart) {
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return AbstractUPCEANReader.findGuardPattern(row, endStart, false, AbstractUPCEANReader.START_END_PATTERN, new Int32Array(AbstractUPCEANReader.START_END_PATTERN.length).fill(0));
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}
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/**
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* @throws NotFoundException
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*/
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static findGuardPatternWithoutCounters(row, rowOffset, whiteFirst, pattern) {
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return this.findGuardPattern(row, rowOffset, whiteFirst, pattern, new Int32Array(pattern.length));
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}
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/**
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* @param row row of black/white values to search
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* @param rowOffset position to start search
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* @param whiteFirst if true, indicates that the pattern specifies white/black/white/...
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* pixel counts, otherwise, it is interpreted as black/white/black/...
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* @param pattern pattern of counts of number of black and white pixels that are being
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* searched for as a pattern
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* @param counters array of counters, as long as pattern, to re-use
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* @return start/end horizontal offset of guard pattern, as an array of two ints
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* @throws NotFoundException if pattern is not found
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*/
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static findGuardPattern(row, rowOffset, whiteFirst, pattern, counters) {
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let width = row.getSize();
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rowOffset = whiteFirst ? row.getNextUnset(rowOffset) : row.getNextSet(rowOffset);
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let counterPosition = 0;
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let patternStart = rowOffset;
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let patternLength = pattern.length;
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let isWhite = whiteFirst;
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for (let x = rowOffset; x < width; x++) {
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if (row.get(x) !== isWhite) {
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counters[counterPosition]++;
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}
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else {
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if (counterPosition === patternLength - 1) {
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if (OneDReader.patternMatchVariance(counters, pattern, AbstractUPCEANReader.MAX_INDIVIDUAL_VARIANCE) < AbstractUPCEANReader.MAX_AVG_VARIANCE) {
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return Int32Array.from([patternStart, x]);
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}
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patternStart += counters[0] + counters[1];
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let slice = counters.slice(2, counters.length);
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for (let i = 0; i < counterPosition - 1; i++) {
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counters[i] = slice[i];
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}
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counters[counterPosition - 1] = 0;
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counters[counterPosition] = 0;
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counterPosition--;
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}
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else {
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counterPosition++;
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}
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counters[counterPosition] = 1;
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isWhite = !isWhite;
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}
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}
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throw new NotFoundException();
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}
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static decodeDigit(row, counters, rowOffset, patterns) {
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this.recordPattern(row, rowOffset, counters);
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let bestVariance = this.MAX_AVG_VARIANCE;
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let bestMatch = -1;
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let max = patterns.length;
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for (let i = 0; i < max; i++) {
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let pattern = patterns[i];
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let variance = OneDReader.patternMatchVariance(counters, pattern, AbstractUPCEANReader.MAX_INDIVIDUAL_VARIANCE);
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if (variance < bestVariance) {
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bestVariance = variance;
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bestMatch = i;
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}
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}
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if (bestMatch >= 0) {
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return bestMatch;
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}
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else {
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throw new NotFoundException();
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}
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}
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}
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// These two values are critical for determining how permissive the decoding will be.
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// We've arrived at these values through a lot of trial and error. Setting them any higher
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// lets false positives creep in quickly.
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AbstractUPCEANReader.MAX_AVG_VARIANCE = 0.48;
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AbstractUPCEANReader.MAX_INDIVIDUAL_VARIANCE = 0.7;
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/**
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* Start/end guard pattern.
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*/
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AbstractUPCEANReader.START_END_PATTERN = Int32Array.from([1, 1, 1]);
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/**
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* Pattern marking the middle of a UPC/EAN pattern, separating the two halves.
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*/
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AbstractUPCEANReader.MIDDLE_PATTERN = Int32Array.from([1, 1, 1, 1, 1]);
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/**
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* end guard pattern.
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*/
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AbstractUPCEANReader.END_PATTERN = Int32Array.from([1, 1, 1, 1, 1, 1]);
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/**
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* "Odd", or "L" patterns used to encode UPC/EAN digits.
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*/
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AbstractUPCEANReader.L_PATTERNS = [
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Int32Array.from([3, 2, 1, 1]),
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Int32Array.from([2, 2, 2, 1]),
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Int32Array.from([2, 1, 2, 2]),
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Int32Array.from([1, 4, 1, 1]),
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Int32Array.from([1, 1, 3, 2]),
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Int32Array.from([1, 2, 3, 1]),
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Int32Array.from([1, 1, 1, 4]),
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Int32Array.from([1, 3, 1, 2]),
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Int32Array.from([1, 2, 1, 3]),
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Int32Array.from([3, 1, 1, 2]),
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];
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