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<blockquote data-quote="EKGuest" data-source="post: 29001583" data-attributes="member: 582168">Formula එක මොන වගේද? උදාහරණ කීපයක් දෙන්න බලන්න.නෙට් එකේ තියෙන කෝඩ් හරියන්නෙ නැද්ද වැඩේට? මේ GeeksForGeeks ජාවා code එකෙන් 100 * ( 2 + 12 ) / 14 වගේ expressions evaluate කරන්න පුලුවන්.<a href="https://www.geeksforgeeks.org/expression-evaluation/" target="_blank">https://www.geeksforgeeks.org/expression-evaluation/</a>[CODE=java]/* A Java program to evaluate agiven expression where tokensare separated by space.*/import java.util.Stack;public class EvaluateString{&nbsp; &nbsp; public static int evaluate(String expression)&nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; char[] tokens = expression.toCharArray();&nbsp; &nbsp; &nbsp; &nbsp; // Stack for numbers: 'values'&nbsp; &nbsp; &nbsp; &nbsp; Stack&lt;Integer&gt; values = new&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Stack&lt;Integer&gt;();&nbsp; &nbsp; &nbsp; &nbsp; // Stack for Operators: 'ops'&nbsp; &nbsp; &nbsp; &nbsp; Stack&lt;Character&gt; ops = new&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Stack&lt;Character&gt;();&nbsp; &nbsp; &nbsp; &nbsp; for (int i = 0; i &lt; tokens.length; i++)&nbsp; &nbsp; &nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // Current token is a&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // whitespace, skip it&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; if (tokens[i] == ' ')&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; continue;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // Current token is a number,&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // push it to stack for numbers&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; if (tokens[i] &gt;= '0' &amp;&amp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; tokens[i] &lt;= '9')&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; StringBuffer sbuf = new&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; StringBuffer();&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // There may be more than one&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // digits in number&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; while (i &lt; tokens.length &amp;&amp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; tokens[i] &gt;= '0' &amp;&amp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; tokens[i] &lt;= '9')&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; sbuf.append(tokens[i++]);&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; values.push(Integer.parseInt(sbuf.&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; toString()));&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // right now the i points to&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // the character next to the digit,&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // since the for loop also increases&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // the i, we would skip one&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // token position; we need to&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // decrease the value of i by 1 to&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // correct the offset.&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; i--;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // Current token is an opening brace,&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // push it to 'ops'&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; else if (tokens[i] == '(')&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; ops.push(tokens[i]);&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // Closing brace encountered,&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // solve entire brace&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; else if (tokens[i] == ')')&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; while (ops.peek() != '(')&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; values.push(applyOp(ops.pop(),&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; values.pop(),&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; values.pop()));&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; ops.pop();&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // Current token is an operator.&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; else if (tokens[i] == '+' ||&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; tokens[i] == '-' ||&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; tokens[i] == '*' ||&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; tokens[i] == '/')&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // While top of 'ops' has same&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // or greater precedence to current&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // token, which is an operator.&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // Apply operator on top of 'ops'&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // to top two elements in values stack&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; while (!ops.empty() &amp;&amp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; hasPrecedence(tokens[i],&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; ops.peek()))&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; values.push(applyOp(ops.pop(),&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; values.pop(),&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; values.pop()));&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // Push current token to 'ops'.&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; ops.push(tokens[i]);&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; // Entire expression has been&nbsp; &nbsp; &nbsp; &nbsp; // parsed at this point, apply remaining&nbsp; &nbsp; &nbsp; &nbsp; // ops to remaining values&nbsp; &nbsp; &nbsp; &nbsp; while (!ops.empty())&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; values.push(applyOp(ops.pop(),&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; values.pop(),&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; values.pop()));&nbsp; &nbsp; &nbsp; &nbsp; // Top of 'values' contains&nbsp; &nbsp; &nbsp; &nbsp; // result, return it&nbsp; &nbsp; &nbsp; &nbsp; return values.pop();&nbsp; &nbsp; }&nbsp; &nbsp; // Returns true if 'op2' has higher&nbsp; &nbsp; // or same precedence as 'op1',&nbsp; &nbsp; // otherwise returns false.&nbsp; &nbsp; public static boolean hasPrecedence(&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; char op1, char op2)&nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; if (op2 == '(' || op2 == ')')&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return false;&nbsp; &nbsp; &nbsp; &nbsp; if ((op1 == '*' || op1 == '/') &amp;&amp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; (op2 == '+' || op2 == '-'))&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return false;&nbsp; &nbsp; &nbsp; &nbsp; else&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return true;&nbsp; &nbsp; }&nbsp; &nbsp; // A utility method to apply an&nbsp; &nbsp; // operator 'op' on operands 'a'&nbsp; &nbsp; // and 'b'. Return the result.&nbsp; &nbsp; public static int applyOp(char op,&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; int b, int a)&nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; switch (op)&nbsp; &nbsp; &nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; case '+':&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return a + b;&nbsp; &nbsp; &nbsp; &nbsp; case '-':&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return a - b;&nbsp; &nbsp; &nbsp; &nbsp; case '*':&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return a * b;&nbsp; &nbsp; &nbsp; &nbsp; case '/':&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; if (b == 0)&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; throw new&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; UnsupportedOperationException(&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &quot;Cannot divide by zero&quot;);&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return a / b;&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; return 0;&nbsp; &nbsp; }&nbsp; &nbsp; // Driver method to test above methods&nbsp; &nbsp; public static void main(String[] args)&nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; System.out.println(EvaluateString.&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; evaluate(&quot;10 + 2 * 6&quot;));&nbsp; &nbsp; &nbsp; &nbsp; System.out.println(EvaluateString.&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; evaluate(&quot;100 * 2 + 12&quot;));&nbsp; &nbsp; &nbsp; &nbsp; System.out.println(EvaluateString.&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; evaluate(&quot;100 * ( 2 + 12 )&quot;));&nbsp; &nbsp; &nbsp; &nbsp; System.out.println(EvaluateString.&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; evaluate(&quot;100 * ( 2 + 12 ) / 14&quot;));&nbsp; &nbsp; }}[/CODE]</blockquote>

[QUOTE="EKGuest, post: 29001583, member: 582168"] Formula එක මොන වගේද? උදාහරණ කීපයක් දෙන්න බලන්න. නෙට් එකේ තියෙන කෝඩ් හරියන්නෙ නැද්ද වැඩේට? මේ GeeksForGeeks ජාවා code එකෙන් 100 * ( 2 + 12 ) / 14 වගේ expressions evaluate කරන්න පුලුවන්. [URL]https://www.geeksforgeeks.org/expression-evaluation/[/URL] [CODE=java]/* A Java program to evaluate a given expression where tokens are separated by space. */ import java.util.Stack; public class EvaluateString { public static int evaluate(String expression) { char[] tokens = expression.toCharArray(); // Stack for numbers: 'values' Stack<Integer> values = new Stack<Integer>(); // Stack for Operators: 'ops' Stack<Character> ops = new Stack<Character>(); for (int i = 0; i < tokens.length; i++) { // Current token is a // whitespace, skip it if (tokens[i] == ' ') continue; // Current token is a number, // push it to stack for numbers if (tokens[i] >= '0' && tokens[i] <= '9') { StringBuffer sbuf = new StringBuffer(); // There may be more than one // digits in number while (i < tokens.length && tokens[i] >= '0' && tokens[i] <= '9') sbuf.append(tokens[i++]); values.push(Integer.parseInt(sbuf. toString())); // right now the i points to // the character next to the digit, // since the for loop also increases // the i, we would skip one // token position; we need to // decrease the value of i by 1 to // correct the offset. i--; } // Current token is an opening brace, // push it to 'ops' else if (tokens[i] == '(') ops.push(tokens[i]); // Closing brace encountered, // solve entire brace else if (tokens[i] == ')') { while (ops.peek() != '(') values.push(applyOp(ops.pop(), values.pop(), values.pop())); ops.pop(); } // Current token is an operator. else if (tokens[i] == '+' || tokens[i] == '-' || tokens[i] == '*' || tokens[i] == '/') { // While top of 'ops' has same // or greater precedence to current // token, which is an operator. // Apply operator on top of 'ops' // to top two elements in values stack while (!ops.empty() && hasPrecedence(tokens[i], ops.peek())) values.push(applyOp(ops.pop(), values.pop(), values.pop())); // Push current token to 'ops'. ops.push(tokens[i]); } } // Entire expression has been // parsed at this point, apply remaining // ops to remaining values while (!ops.empty()) values.push(applyOp(ops.pop(), values.pop(), values.pop())); // Top of 'values' contains // result, return it return values.pop(); } // Returns true if 'op2' has higher // or same precedence as 'op1', // otherwise returns false. public static boolean hasPrecedence( char op1, char op2) { if (op2 == '(' || op2 == ')') return false; if ((op1 == '*' || op1 == '/') && (op2 == '+' || op2 == '-')) return false; else return true; } // A utility method to apply an // operator 'op' on operands 'a' // and 'b'. Return the result. public static int applyOp(char op, int b, int a) { switch (op) { case '+': return a + b; case '-': return a - b; case '*': return a * b; case '/': if (b == 0) throw new UnsupportedOperationException( "Cannot divide by zero"); return a / b; } return 0; } // Driver method to test above methods public static void main(String[] args) { System.out.println(EvaluateString. evaluate("10 + 2 * 6")); System.out.println(EvaluateString. evaluate("100 * 2 + 12")); System.out.println(EvaluateString. evaluate("100 * ( 2 + 12 )")); System.out.println(EvaluateString. evaluate("100 * ( 2 + 12 ) / 14")); } } [/CODE] [/QUOTE]

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