/* ( 40 ) 41 * 42 + 43 - 45 / 47 */ import java.util.Scanner; public class Program { public static boolean TESTMODE = false; public static boolean isJunkCharacter(char character) { if (TESTMODE) { System.out.println("Calling isJunkCharacter."); } return character <= 32 || 65 <= character && character <= 90 || 97 <= character && character <= 122; } public static boolean isDigit(char character) { if (TESTMODE) { System.out.println("Calling isDigit."); } return 48 <= character && character <= 57; } public static boolean isDigitArray(char[] arr) { if (TESTMODE) { System.out.println("Calling isDigitArray."); } for (Character character: arr) { if (!(isDigit(character))) { return false; } } return true; } public static int countValidItems(char[] arr) { int validItems = 0; for (Character character: arr) { if (character != 0) { validItems++; } } return validItems; } public static int countDigits(int a) { if (TESTMODE) { System.out.println("Calling countDigits."); } if (a == 0) { return 1; } int digits = 0; while (a != 0) { a /= 10; digits++; } return digits; } public static int pow(int a, int b) { if (TESTMODE) { System.out.println("Calling pow(" + a + ", " + b + ")."); } int c = 1; for (int i = 0; i < b; i++) { c *= a; } if (TESTMODE) { System.out.println("Returning " + c + "."); } return c; } public static int getCharArrayAsInteger(char[] arr) { int arrLength = countValidItems(arr); if (TESTMODE) { System.out.print("Calling getCharArrayAsInteger({"); for (int i = 0; i < arrLength; i++) { System.out.print(arr[i]); if (i + 1 != arrLength) { System.out.println(", "); } } System.out.println("}). "); } int startIndex = 0; if (arr[0] == '-') { startIndex++; } int integer = 0; int a, b; for (int i = startIndex; i < arrLength; i++) { a = arr[i] - 48; b = pow(10, arrLength - i - 1); integer += a * b; } if (TESTMODE) { System.out.print("Returning "); if (startIndex == 1) { System.out.print("-"); } System.out.println(integer + "."); } if (startIndex == 0) { return integer; } else { return -integer; } } public static char[] getIntegerAsCharArray(int a) { if (TESTMODE) { System.out.println("Calling getIntegerAsCharArray(" + a + ")."); } int digits = countDigits(a); int startIndex = 0; if (a < 0) { digits++; startIndex++; a = -a; } char[] arr = new char[digits]; if (startIndex == 1) { arr[0] = '-'; } for (int i = startIndex; i < digits; i++) { arr[startIndex + digits - i - 1] = (char) (a % 10 + 48); a /= 10; } if (TESTMODE) { System.out.print("Returning {"); print1DArray(arr); System.out.println("}."); } return arr; } public static int countJunkCharacters(char[] arr) { if (TESTMODE) { System.out.println("Calling countJunkCharacters."); } int JunkCharacters = 0; for (char character: arr) { if (isJunkCharacter(character)) { JunkCharacters++; } } return JunkCharacters; } public static char[] getWithoutJunkCharacters(char[] arr) { if (TESTMODE) { System.out.println("Calling getWithoutJunkCharacters."); } char[] newArr = new char[arr.length - countJunkCharacters(arr)]; for (int i = 0, j = 0; i < arr.length; i++) { if (arr[i] > 32) { newArr[j] = arr[i]; j++; } } return newArr; } public static int getMaximumSeparableLength(char[] arr) { if (TESTMODE) { System.out.println("Calling getMaximumSeparableLength."); } if (arr.length <= 1) { return arr.length; } int length = 1; int maximumLength = 1; for (int i = 0; i + 1 < arr.length; i++) { if (!(isDigit(arr[i]) && isDigit(arr[i + 1]))) { if (length > maximumLength) { maximumLength = length; } length = 1; } else { length += 1; } } if (length > maximumLength) { return length; } return maximumLength; } public static int countSeparables(char[] arr) { if (TESTMODE) { System.out.println("Calling countSeparables."); } int separables = 1; for (int i = 0; i + 1 < arr.length; i++) { if (!(isDigit(arr[i]) && isDigit(arr[i + 1]))) { separables++; } } return separables; } public static char[][] getSeparated(char[] arr) { if (TESTMODE) { System.out.println("Calling getSeparated."); } char[] newArr = getWithoutJunkCharacters(arr); int separables = countSeparables(newArr); int maximumSeparableLength = getMaximumSeparableLength(newArr); char[][] separated = new char[separables][maximumSeparableLength]; for (int i = 0, j = 0, k = 0; i < newArr.length; i++) { separated[j][k] = newArr[i]; if (i + 1 != newArr.length) { if (!(isDigit(newArr[i]) && isDigit(newArr[i + 1]))) { j++; k = 0; } else { k++; } } } return separated; } public static char[][] getSlice(char[][] arr, int startIndex, int endIndex) { if (TESTMODE) { System.out.print("Calling getSlice({"); print2DArray(arr); System.out.println("}, " + startIndex + ", " + endIndex + ")."); } char newArr[][] = new char[endIndex - startIndex][arr[0].length]; for (int i = 0, j = startIndex; j < endIndex; i++, j++) { for (int k = 0; k < arr[0].length; k++) { newArr[i][k] = arr[j][k]; } } if (TESTMODE) { System.out.print("Returning {"); print2DArray(newArr); System.out.println("}."); } return newArr; } public static char[][] getRSlice(char[][] arr, int startIndex, int endIndex) { if (TESTMODE) { System.out.print("Calling getRSlice({"); print2DArray(arr); System.out.println("}, " + startIndex + ", " + endIndex + ")."); } char newArr[][] = new char[startIndex - endIndex + arr.length][arr[0].length]; for (int i = 0; i < startIndex; i++) { for (int j = 0; j < arr[0].length; j++) { newArr[i][j] = arr[i][j]; } } for (int i = 0; i + endIndex < arr.length; i++) { for (int j = 0; j < arr[0].length; j++) { newArr[startIndex + i][j] = arr[endIndex + i][j]; } } if (TESTMODE) { System.out.print("Returning {"); print2DArray(newArr); System.out.println("}."); } return newArr; } public static int index(char a, char[][] arr) { if (TESTMODE) { System.out.println("Calling index."); } int startIndex = 0; if (a == '-') { startIndex++; } for (int i = startIndex; i < arr.length; i++) { if (arr[i][0] == a) { return i; } } return -1; } public static int max(int a, int b) { if (TESTMODE) { System.out.println("Calling max."); } if (a >= b) { return a; } return b; } public static int min(int a, int b) { if (TESTMODE) { System.out.println("Calling min."); } if (a <= b) { return a; } return b; } public static char[][] getConnectedSlices(char[][] arr1, char[][] arr2) { if (TESTMODE) { System.out.println("Calling getConnectedSlices."); } char[][] newArr = new char[arr1.length + arr2.length][max(arr1[0].length, arr2[0].length)]; for (int i = 0; i < arr1.length; i++) { for (int j = 0; i < arr1[0].length; j++) { newArr[i][j] = arr1[i][j]; } } for (int i = 0; i < arr2.length; i++) { for (int j = 0; j < arr2[0].length; j++) { newArr[i + arr1.length][j] = arr2[i][j]; } } return newArr; } public static void print2DArray(char[][] arr) { for (char[] subArr: arr) { for (Character character: subArr) { System.out.print(character); } System.out.print(" "); } } public static void print1DArray(char[] arr) { for (Character character: arr) { System.out.print(character); } } public static char[][] getWithInserted(char[] arr1, char[][] arr2, int index) { if (TESTMODE) { System.out.print("Calling getWithInserted({"); print1DArray(arr1); System.out.print("}, {"); print2DArray(arr2); System.out.println("}, " + index + ")."); } if (arr2.length == 0) { char[][] newArr = new char[1][arr1.length]; for (int i = 0; i < arr1.length; i++) { newArr[0][i] = arr1[i]; } return newArr; } char[][] newArr = new char[arr2.length + 1][max(arr1.length, arr2[0].length)]; for (int i = 0; i < index; i++) { for (int j = 0; j < arr2[0].length; j++) { newArr[i][j] = arr2[i][j]; } } for (int i = 0; i < arr1.length; i++) { newArr[index][i] = arr1[i]; } for (int i = index; i < arr2.length; i++) { for (int j = 0; j < arr2[0].length; j++) { newArr[i + 1][j] = arr2[i][j]; } } return newArr; } public static char[] getEvaluated(char[][] arr) { if (TESTMODE) { System.out.println("Calling getEvaluated."); } if (arr.length == 3) { int a = getCharArrayAsInteger(arr[0]); int b = getCharArrayAsInteger(arr[2]); switch (arr[1][0]) { case '*': return getIntegerAsCharArray(a * b); case '+': return getIntegerAsCharArray(a + b); case '-': return getIntegerAsCharArray(a - b); case '/': return getIntegerAsCharArray(a / b); } } return new char[0]; } public static char[] getSimplified(char[][] arr) { if (TESTMODE) { System.out.println("Calling getSimplified."); } int startIndex; int endIndex; int justIndex; while (arr.length != 1) { startIndex = index('(', arr); if (startIndex != -1) { endIndex = arr.length; int depth = 0; for (int i = startIndex + 1; i < arr.length; i++) { if (arr[i][0] == '(') { depth++; } else if (arr[i][0] == ')' && depth == 0) { endIndex = i; break; } else if (arr[i][0] == ')') { depth--; } } if (endIndex - startIndex == 4) { arr = getWithInserted(getEvaluated(getSlice(arr, startIndex + 1, endIndex)), getRSlice(arr, startIndex, endIndex + 1), startIndex); } else { arr = getWithInserted(getSimplified(getSlice(arr, startIndex + 1, endIndex)), getRSlice(arr, startIndex, endIndex + 1), startIndex); } continue; } startIndex = index('*', arr); justIndex = index('/', arr); if (startIndex != -1 || justIndex != -1) { if (startIndex != -1 && justIndex != -1) { startIndex = min(startIndex, justIndex); } else if (justIndex != -1) { startIndex = justIndex; } startIndex--; endIndex = startIndex + 2; arr = getWithInserted(getEvaluated(getSlice(arr, startIndex, endIndex + 1)), getRSlice(arr, startIndex, endIndex + 1), startIndex); continue; } startIndex = index('+', arr); justIndex = index('-', arr); if (startIndex != -1 || justIndex != -1) { if (startIndex != -1 && justIndex != -1) { startIndex = min(startIndex, justIndex); } else if (justIndex != -1) { startIndex = justIndex; } startIndex--; endIndex = startIndex + 2; arr = getWithInserted(getEvaluated(getSlice(arr, startIndex, endIndex + 1)), getRSlice(arr, startIndex, endIndex + 1), startIndex); continue; } } return arr[0]; } public static void main(String[] args) { if (TESTMODE) { System.out.println("Calling main."); } Scanner reader = new Scanner(System.in); System.out.print("Please type any calculations: "); String line = reader.nextLine(); if (line.length() == 0) { System.out.println("\nBecause of getting given empty input this foreword text was printed.\n"); System.out.println("Hello! I wrote this calculator."); System.out.println("Most lines went for defining methods for arrays, but I'm very proud of it, because it is the best Java code I've yet made.\n"); System.out.println("There is still small risk for bugs to exist, so I would ask you to try this code with 5 different inputs, if the output isn't correct or other errors appear, please comment the output, but read the following introduction first:\n"); System.out.println("Introduction:"); System.out.println("~> Type any calculation, which:"); System.out.println("~>~> Only uses operators: +, -, * and /."); System.out.println("~>~> Only uses positive integers. (0 - n is valid.)"); System.out.println("~>~> Can use parentheses, but each parenthese symbol should have a pair."); System.out.println("~>~> Don't use 2 operators in row."); return; } System.out.println(line); char[] characters = line.toCharArray(); System.out.println(); char[][] separated = getSeparated(characters); char[] evaluated = getSimplified(separated); System.out.print("Result: "); for (Character character: evaluated) { System.out.print(character); } } }

JavaCalculator