Program to evaluate simple expressions - GeeksQuiz
You are given a string that represent an expression of digits and operands. E.g. 1+2*3, 1-2+4. You need to evaluate the string or the expression. NO BODMAS is followed. If the expression is of incorrect syntax return -1.
Test cases:
a) 1+2*3 will be evaluated to 9.
b) 4-2+6*3 will be evaluated to 24.
c) 1++2 will be evaluated to -1(INVALID).
Also, in the string spaces can occur. For that case we need to ignore the spaces. Like :- 1*2 -1 is equals to 1
The above code doesn’t handle spaces. We can handle spaces by first removing all spaces from the given string. A better solution is to handle spaces in single traversa
Read full article from Program to evaluate simple expressions - GeeksQuiz
You are given a string that represent an expression of digits and operands. E.g. 1+2*3, 1-2+4. You need to evaluate the string or the expression. NO BODMAS is followed. If the expression is of incorrect syntax return -1.
Test cases:
a) 1+2*3 will be evaluated to 9.
b) 4-2+6*3 will be evaluated to 24.
c) 1++2 will be evaluated to -1(INVALID).
Also, in the string spaces can occur. For that case we need to ignore the spaces. Like :- 1*2 -1 is equals to 1
int evaluate(char *exp){ // Base Case: Given expression is empty if (*exp == '\0') return -1; // The first character must be an operand, find its value int res = value(exp[0]); // Traverse the remaining characters in pairs for (int i = 1; exp[i]; i += 2) { // The next character must be an operator, and // next to next an operand char opr = exp[i], opd = exp[i+1]; // If next to next character is not an operand if (!isOperand(opd)) return -1; // Update result according to the operator if (opr == '+') res += value(opd); else if (opr == '-') res -= value(opd); else if (opr == '*') res *= value(opd); else if (opr == '/') res /= value(opd); // If not a valid operator else return -1; } return res;}Read full article from Program to evaluate simple expressions - GeeksQuiz
