1 | package org.expeditee;
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2 |
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3 | import java.text.DateFormat;
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4 | import java.text.ParseException;
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5 | import java.text.SimpleDateFormat;
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6 | import java.util.Collections;
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7 | import java.util.Date;
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8 | import java.util.HashSet;
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9 | import java.util.LinkedList;
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10 | import java.util.List;
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11 |
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12 | import org.expeditee.stats.Formatter;
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13 |
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14 | /**
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15 | * Static collection of various helper methods.
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16 | *
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17 | * @author cts16
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18 | *
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19 | */
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20 | public class Util {
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21 |
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22 | /**
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23 | * Using Microsofts commandline convention: Args seperated with white
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24 | * spaces. Options with white spaces enclosed with quotes. Args with quotes
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25 | * must be double quoted args1 args2=sfasas args3="option with spaces"
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26 | * arg""4""
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27 | *
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28 | * @param args
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29 | * Null and empty excepted
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30 | * @return An array of args. null if none provided
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31 | */
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32 | public static String[] parseArgs(String args) {
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33 |
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34 | if (args == null)
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35 | return null;
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36 |
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37 | args = args.trim();
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38 | if (args.length() == 0)
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39 | return null;
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40 |
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41 | List<String> vargs = new LinkedList<String>();
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42 | StringBuilder sb = new StringBuilder();
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43 | boolean quoteOn = false;
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44 | for (int i = 0; i < args.length(); i++) {
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45 |
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46 | char c = args.charAt(i);
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47 | if (c == ' ' && !quoteOn) {
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48 |
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49 | // Extract arg
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50 | vargs.add(sb.toString());
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51 | sb = new StringBuilder();
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52 |
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53 | // Consume white spaces
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54 | while (args.charAt(++i) == ' ' && i < args.length()) {
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55 | }
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56 | i--;
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57 |
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58 | } else if (c == '\"') {
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59 | // If double quoted
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60 | if (args.length() >= (i + 2) && args.charAt(i + 1) == '\"') {
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61 |
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62 | sb.append(c); // add escaped
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63 | i++;
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64 |
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65 | } else {
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66 | quoteOn = !quoteOn;
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67 | }
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68 |
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69 | } else {
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70 | sb.append(c);
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71 | }
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72 | }
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73 |
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74 | if (sb.length() > 0)
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75 | vargs.add(sb.toString());
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76 |
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77 | if (vargs.size() == 0)
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78 | return null;
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79 | else
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80 | return vargs.toArray(new String[vargs.size()]);
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81 | }
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82 |
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83 | /**
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84 | * Reverse of parseArgs
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85 | *
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86 | * @return Null if args is null or empty / all whitespace
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87 | */
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88 | public static String formatArgs(String[] args) {
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89 | if (args == null)
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90 | return null;
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91 |
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92 | StringBuilder sb = new StringBuilder();
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93 |
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94 | for (String s : args) {
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95 | if (s == null)
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96 | continue;
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97 |
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98 | // Escape quotes
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99 | StringBuilder formatted = new StringBuilder(s.replaceAll("\"",
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100 | "\"\""));
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101 |
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102 | // Encapsulate spaces
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103 | int index = formatted.indexOf(" ");
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104 | if (index >= 0) {
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105 | formatted.insert(index, "\"");
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106 | formatted.append('\"');
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107 | }
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108 |
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109 | if (sb.length() > 0)
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110 | sb.append(' ');
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111 | sb.append(formatted);
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112 | }
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113 |
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114 | return sb.length() > 0 ? sb.toString() : null;
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115 | }
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116 |
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117 | /**
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118 | * Parses a date from the given string.
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119 | *
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120 | * @param dateString
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121 | * The string to parse.
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122 | *
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123 | * @return
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124 | * The date parsed from the string.
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125 | *
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126 | * @throws ParseException
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127 | */
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128 | public static Date parseDate(String dateString) throws ParseException {
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129 | // Select the best match for a date or time format
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130 | DateFormat df = null;
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131 | if (dateString.length() > Formatter.DATE_FORMAT.length()) {
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132 | df = new SimpleDateFormat(Formatter.DATE_TIME_FORMAT);
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133 | } else if (dateString.length() <= Formatter.TIME_FORMAT.length()) {
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134 | df = new SimpleDateFormat(Formatter.TIME_FORMAT);
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135 | } else {
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136 | df = new SimpleDateFormat(Formatter.DATE_FORMAT);
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137 | }
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138 | Date date = df.parse(dateString);
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139 | return date;
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140 | }
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141 |
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142 | /**
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143 | * Sets all members of the given array to the given value.
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144 | *
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145 | * @param arr
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146 | * The array to initialise.
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147 | *
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148 | * @param val
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149 | * The value to set each element to.
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150 | */
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151 | public static void initialiseBoolArray(boolean[] arr, boolean val)
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152 | {
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153 | for (int i = 0; i < arr.length; i++) arr[i] = val;
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154 | }
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155 |
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156 | /** Whether or not the system has been checked to see if the Java version is >= 1.6 */
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157 | private static boolean _minimum_version6_checked = false;
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158 | /** Whether or not the Java version running is >= 1.6 */
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159 | private static boolean _minimum_version6 = false;
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160 |
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161 | /**
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162 | * Checks if the running version of Java is >= 1.6.
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163 | *
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164 | * @return
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165 | * True if the Java version is >= 1.6, false otherwise.
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166 | */
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167 | public static boolean isMinimumVersion6()
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168 | {
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169 | // If we haven't checked yet, do so
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170 | if (!_minimum_version6_checked) {
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171 | String full_version = System.getProperty("java.version");
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172 | String[] version_parts = full_version.split("\\.");
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173 | if (version_parts.length>=2) {
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174 | String version_str = version_parts[0] + "." + version_parts[1];
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175 | double version = Double.parseDouble(version_str);
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176 | if (version >= 1.6) {
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177 | _minimum_version6 = true;
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178 | }
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179 | }
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180 |
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181 | _minimum_version6_checked = true;
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182 | }
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183 |
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184 | return _minimum_version6;
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185 | }
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186 |
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187 | /**
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188 | * Returns an array of roots to the quadratic equation ax^2 + bx + c = 0.
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189 | * Will be null, or contain 1 or 2 values depending on the constants given.
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190 | */
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191 | public static double[] quadraticEquation(double a, double b, double c)
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192 | {
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193 | // Calculate the discriminant
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194 | double discriminant = b * b - 4 * a * c;
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195 |
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196 | // See how many roots we have
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197 | if (discriminant < 0) {
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198 | return null;
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199 | } else if (discriminant == 0) {
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200 | double[] ret = new double[1];
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201 | ret[0] = -b / (2 * a);
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202 | return ret;
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203 | } else {
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204 | double[] ret = new double[2];
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205 | ret[0] = (-b + Math.sqrt(discriminant)) / (2 * a);
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206 | ret[1] = (-b - Math.sqrt(discriminant)) / (2 * a);
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207 | return ret;
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208 | }
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209 | }
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210 |
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211 | public static double[] toDoubleArray(float[] floatArray)
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212 | {
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213 | if (floatArray == null) return null;
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214 |
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215 | double[] ret = new double[floatArray.length];
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216 |
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217 | for (int i = 0; i < floatArray.length; i++) {
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218 | ret[i] = floatArray[i];
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219 | }
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220 |
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221 | return ret;
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222 | }
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223 |
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224 | /** Creates a hash-set from an array. */
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225 | public static <T> HashSet<T> hashSetFromArray(T[] array)
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226 | {
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227 | if (array == null) return null;
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228 |
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229 | HashSet<T> ret = new HashSet<T>();
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230 | for (T element : array) ret.add(element);
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231 |
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232 | return ret;
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233 | }
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234 |
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235 | /** Returns the string which is n concatenations of the given character. */
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236 | public static String nCopiesOf(int n, char character)
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237 | {
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238 | if (n < 0) {
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239 | return null;
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240 | } else if (n == 0) {
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241 | return "";
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242 | } else {
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243 | return String.join("", Collections.nCopies(n, Character.toString(character)));
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244 | }
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245 | }
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246 |
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247 | /** Returns the linear interpolation between a and b. */
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248 | public static float lerp(float a, float b, float t)
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249 | {
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250 | return t * (b - a) + a;
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251 | }
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252 | }
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