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Program to convert a infix expression in to postfix and prefix expression in php?
To convert an infix expression to postfix and prefix in PHP, you can implement the Shunting Yard algorithm for postfix conversion and a modified approach for prefix conversion. For postfix, you use a stack to reorder operators based on their precedence and associativity while scanning the infix expression. For prefix, you can reverse the infix expression, convert it to postfix, and then reverse the resulting postfix expression. Here’s a brief code outline for both conversions: function infixToPostfix($infix) { // Implement the Shunting Yard algorithm to convert infix to postfix } function infixToPrefix($infix) { // Reverse the infix expression // Convert to postfix using infixToPostfix // Reverse the postfix result to get prefix } You would need to handle operators, parentheses, and precedence rules within these functions.
Write an algorithm to evaluate an infix expression using stack by converting?
To evaluate an infix expression using a stack, first convert the infix expression to postfix (Reverse Polish Notation) using the Shunting Yard algorithm. In this algorithm, use a stack to temporarily hold operators and output the operands and operators in the correct order based on their precedence and associativity. Once the expression is in postfix form, use another stack to evaluate it by processing each token: push operands onto the stack and pop the necessary number of operands for each operator, performing the operation and pushing the result back onto the stack. The final result will be the only value left in the stack after processing the entire postfix expression.
Algorithm for infix to prefix conversion?
Algorithm to Convert Infix to Prefix FormSuppose A is an arithmetic expression written in infix form. The algorithm finds equivalent prefix expression B.Step 1. Push ")" onto STACK, and add "(" to end of the AStep 2. Scan A from right to left and repeat step 3 to 6 for each element of A until the STACK is emptyStep 3. If an operand is encountered add it to BStep 4. If a right parenthesis is encountered push it onto STACKStep 5. If an operator is encountered then:a. Repeatedly pop from STACK and add to B each operator (on the top of STACK) which has same or higher precedence than the operator.b. Add operator to STACKStep 6. If left parenthesis is encontered thena. Repeatedly pop from the STACK and add to B (each operator on top of stack until a left parenthesis is encounterd)b. Remove the left parenthesisStep 7. Exit
How do infix notation and postfix notation differ?
It's simply a matter of where the operators are placed in relation to their operands: infix: X + Y prefix: + X Y postfix: X Y + All of the above are equivalent. Prefix notation is also known as Polish notation, hence postfix is also known as reverse Polish notation. Given the infix equation A * B + C / D, the order of evaluation is always parenthesis, orders, divide/multiply, add/subtract (PODMAS), thus we must multiply A by B first, then divide C by D, and finally add the two results together. If we wish to perform the addition first, then we must re-write the equation with parenthesis: A * (B + C) / D. With postfix and prefix notation, operator precedence becomes superfluous because we always evaluate these expressions in left-to-right order: Infix A * B + C / D becomes postfix A B * C D / + or prefix / * A + B C D Infix A * (B + C) / D becomes postfix A B C + * D / or prefix + * A B / C D When we eliminate operator precedence with postfix or prefix notation, we greatly simplify the algorithm required to evaluate complex expressions. For example, given the postfix expression A B C + * D /, we simply read the symbols one at a time, placing them on a stack, until we encounter an operator. We then pop the first two elements off the stack, perform the operation, and then pop the result back on the stack. We repeat this process until there are no more symbols left, at which point the stack holds just one value: the result. With prefix notation, we place the operators on the stack instead of the operands. When we read the first operand we simply store it in an accumulator. We continue pushing operators onto the stack until we encounter the second operand, at which point we can pop the first operator off the stack, perform the operation and update the accumulator. We repeat this process until there are no symbols left, at which point the accumulator holds the final result. Note that when presented with an infix expression, a machine has to convert the expression to the equivalent prefix or postfix expression before it can be evaluated. By eliminating this conversion process, computation by machine can be performed with much greater speed.
Which data structure is needed to convert infix notations to post fix notations?
stack is the basic data structure needed to convert infix notation to postfix
Which data structure convert logical to physical address?
Linear data structure is used to convert the logical address to physical address .Stack is used in this and the various conversion such as postfix,prefix and infix notation are come in this
Algorithm for conversion from prefix to infix?
The belt-and-braces technique is easy enough: > > prefix_to_infix(stream, stack) > if stack is not empty > pop a node off the stack > if this node represents an operator > write an opening parenthesis to stream > prefix_to_infix(stream, stack) > write operator to stream > prefix_to_infix(stream, stack) > write a closing parenthesis to stream > else > write value to stream > endif > endif > endfunc
How do you convert a prefix expression to postfix using recursion?
struct stack { char ele; struct stack *next; }; void push(int); int pop(); int precedence(char); struct stack *top = NULL; int main() { char infix[20], postfix[20]; int i=0,j=0; printf("ENTER INFIX EXPRESSION: "); gets(infix); while(infix[i]!='\0') { if(isalnum(infix[i])) postfix[j++]=infix[i]; else { if(top==NULL) push(infix[i]); else { while(top!=NULL && (precedence(top->ele)>=precedence(infix[i]))) postfix[j++]=pop(); push(infix[i]); } } ++i; } while(top!=NULL) postfix[j++]=pop(); postfix[j]='\0'; puts(postfix); getchar(); return 0; } int precedence(char x) { switch(x) { case '^': return 4; case '*': case '/': return 3; case '+': case '-': return 2; default: return 0; } } void push(int x) { int item; struct stack *tmp; if(top==NULL) { top=(struct stack *)malloc(sizeof(struct stack)); top->ele=x; top->next=NULL; } else { tmp=top; top->ele=x; top->next=tmp; } } int pop() { struct stack *tmp; int item; if(top==NULL) puts("EMPTY STACK"); else if(top->next==NULL) { tmp=top; item=top->ele; top=NULL; free(tmp); } else { tmp=top; item=top->ele; top=top->next; free(tmp); } return item; }
What are the stack operation?
there are two operations you can do with a STACK one is PUSH operation and the other is POP operation
Write a java program that implements stack ADT converts infix expression to postfix form evaluates the postfix expression?
// made by vijay NITJ #include<iostream.h> #include<string.h> #include<stdio.h> #include<math.h> int precedence(char); void main() { char q[20]; char p[20]; char stack[20]; int tp=-1,ts=0; stack[0]='('; cout<<stack; int i=0, f=1; cout<<"enter the prefix expression "; gets(q); int l=strlen(q); q[l]=')'; while(ts!=-1) { if(q[i]>=47 && q[i]<=58 q[i]<=65 && q[i]<=90 q[i]<=97 && q[i]>=122) { p[++tp]=q[i]; } else if(q[i]=='(') stack[++ts]=q[i]; else if(q[i]=='+' q[i]=='-' q[i]=='*' q[i]=='/') { if(stack[ts]=='(') stack[++ts]=q[i]; else { while(stack[ts]!='(') { int p1=precedence(q[i]); int p2=precedence(stack[ts]); if(p2>=p1) p[++tp]=stack[ts--]; else { f=0; break; } } if(f==0) stack[++ts]=q[i]; } } else if(q[i]==')') { while(stack[ts]!='(') { p[++tp]=stack[ts--]; } ts--; } i++; } for(int j=0; j<=tp;j++) { cout<<p[j]; } //precedence program int precedence(char a) { if(a=='+' a=='-') return 1; else if(a=='*' a=='/') return 2; }
Example program of how to convert infix notation to postfix notation and prefix notation?
/**************************//**********cReDo**********//*****mchinmay@live.com***///C PROGRAM TO CONVERT GIVEN VALID INFIX EXPRESSION INTO POSTFIX EXPRESSION USING STACKS.#include#include#include#define MAX 20char stack[MAX];int top=-1;char pop();void push(char item);int prcd(char symbol){switch(symbol){case '+':case '-':return 2;break;case '*':case '/':return 4;break;case '^':case '$':return 6;break;case '(':case ')':case '#':return 1;break;}}int isoperator(char symbol){switch(symbol){case '+':case '-':case '*':case '/':case '^':case '$':case '(':case ')':return 1;break;default:return 0;}}void convertip(char infix[],char postfix[]){int i,symbol,j=0;stack[++top]='#';for(i=0;iprcd(stack[top]))push(symbol);else{while(prcd(symbol)
What is stack operation in 8085 microprocessor?
STACK operation in 8085 microprocessor.The stack is a reserved area of the memory in RAM where temporary information may be stored. An 8-bit stack pointer is used to hold the address of the most recent stack entry. This location which has the most recent entry is called as the top of the stack.When the information is written on the stack, the operation is called PUSH. When the information is read from the stack, the operation is called POP. The stack works on the principle of Last in First Out or Fist in Lat Out
