int calculate(string s) {
vector<string> numberAndOps = tokenizeStringToVector(s);
int n = numberAndOps.size();
int d[n], p = 0, q = 0;
char c[n];
for (int i = 0; i < n; i++) {
if (isMultiOrDivide(numberAndOps[i])) {
int op1 = d[p - 1];
int op2 = toInt(numberAndOps[i + 1]);
if (numberAndOps[i] == "/") {
d[p - 1] = op1 / op2;
} else {
d[p - 1] = op1 * op2;
}
i++;
} else if (isPlusOrMinus(numberAndOps[i])) {
c[q++] = numberAndOps[i][0];
} else {
d[p++] = toInt(numberAndOps[i]);
}
}
int ans = d[0];
for (int i = 0; i < q; i++) {
if (c[i] == '+') {
ans += d[i + 1];
} else {
ans -= d[i + 1];
}
}
return ans;
}
bool sumExpressionDash(char s[],int &position)
{
if (isPlusOrMinus(s[position]))
{
int current = position + 1;
if (multiplicationExpression(s, current) && (sumExpressionDash(s, current)))
{
position = current;
return true;
}
else
return true;
}
else
{
return true;
}
}
