3AC-Java

import java.io.*; class Assg5 { private static final char[][] precedence = { { '/', '1' }, { '*', '1' }, { '+', '2' }, { '-', '2' } };
private static int precedenceOf(String t) { char token = t.charAt(0); for (int i = 0; i < precedence.length; i++) { if (token == precedence[i][0]) { return Integer.parseInt(precedence[i][1] + ""); } } return -1; } public static void main(String[] args) throws Exception { int i, j, opc = 0; char token; boolean processed[]; String[][] operators = new String[10][2]; String expr = "", temp; BufferedReader in = new BufferedReader(new InputStreamReader(System.in)); System.out.print("\nEnter an expression: "); expr = in.readLine(); processed = new boolean[expr.length()]; for (i = 0; i < processed.length; i++) { processed[i] = false; } for (i = 0; i < expr.length(); i++) { token = expr.charAt(i); for (j = 0; j < precedence.length; j++) { if (token == precedence[j][0]) { operators[opc][0] = token + ""; operators[opc][1] = i + ""; opc++; break; } } } System.out.println("\n-------------------------------"); System.out.println(" Operators "); System.out.println("-------------------------------"); System.out.println("\nOperators \tLocation number\n "); for (i = 0; i < opc; i++) { System.out.println(operators[i][0] + "\t\t" + operators[i][1]); } for (i = opc - 1; i >= 0; i--) { for (j = 0; j < i; j++) { if (precedenceOf(operators[j][0]) > precedenceOf(operators[j + 1][0])) { temp = operators[j][0]; operators[j][0] = operators[j + 1][0];
operators[j + 1][0] = temp; temp = operators[j][1]; operators[j][1] = operators[j + 1][1]; operators[j + 1][1] = temp; } } } System.out.println("\n-------------------------------"); System.out.println(" Operators (Sorted) "); System.out.println("-------------------------------"); System.out.println("\nOperators \tLocation number \n"); for (i = 0; i < opc; i++) { System.out.println(operators[i][0] + "\t\t" + operators[i][1]); } System.out.println(); for (i = 0; i < opc; i++) { j = Integer.parseInt(operators[i][1] + ""); String op1 = "", op2 = ""; if (processed[j - 1] == true) { if (precedenceOf(operators[i - 1][0]) == precedenceOf(operators[i][0])) { op1 = "t" + i; } else { for (int x = 0; x < opc; x++) { if ((j - 2) == Integer.parseInt(operators[x][1])) { op1 = "t" + (x + 1) + ""; } } } } else { op1 = expr.charAt(j - 1) + ""; } if (processed[j + 1] == true) { for (int x = 0; x < opc; x++) { if ((j + 2) == Integer.parseInt(operators[x][1])) { op2 = "t" + (x + 1) + ""; } } } else { op2 = expr.charAt(j + 1) + ""; } System.out.println("t" + (i + 1) + " = " + op1 + operators[i][0] + op2); processed[j] = processed[j - 1] = processed[j + 1] = true; } System.out.println();
} }