K and R Exercise 5-10Write the program expr, which evaluates a reverse Polish expression  from the command line, where each operator or operand is a separate  argument. For example,expr 2 3 4 + *evaluates2 * (3+4)#include <stdio.h>#include expression_parser.hint parse_polish(int size, char *expression[]){    char *entry;    int temp1, temp2;    if (expression[1] && ((isdigit(*expression[1]) &&        isdigit(*expression[2])))) {        stack_init(&size, expression);        expression++;        for ( ; *expression; expression++) {            if (isdigit(*(entry = *expression)))                push(atoi(entry));            else {                switch (*entry) {                    case '+':                        push(pop() + pop());                        break;                    case '-':                        temp1 = pop();                        temp2 = pop();                        push(temp1 - temp2);                        break;                    case '*':                        push(pop() * pop());                        break;                    case '/':                        temp1 = pop();                        temp2 = pop();                        if (!(temp2))                            return -1;                        else                             push(temp1 / temp2);                        break;                    default:                        return -1;                }            }        }        return pop();    } else           return -1;}Repository
Basic Reverse Polish CL Parser
c;programming challenge;math expression eval