C / C++ / MFC

E→E+T|E-T|T
T→T*F| T/F|F
F→(E)|i

<pre>
#include<stdio.h>    
#include<string> 
 using namespace std;
 int pos = 0;
 string str = "1+2*3-4";
 double E();
 double T();
 double F();

int main() {
	double v = E();
	printf("%f", v);
	getchar();
	return 0;
}

double E() {
	double v = 0;
	char c = str.at(pos);
	if (c == '+') {
		pos++;
		v = E() + T();
	}
	else if (c == '-') {
		pos++;
		v = E() - T();
	}
	else {
		pos++;
		v = T();
	}
	return v;
}

 double T() {
	double v = 0;
	char c = str.at(pos);
	if (c == '*') {
		pos++;
		v = T() * F();
	}
	else if (c == '/') {
		pos++;
		v = T() / F();
	}
	else {
		pos++;
		v = F();
	}
	return v;
}

 double F() {
	char c = str.at(pos);
	if (c == '(') {
		pos++;
		double v = E();
		c = str.at(pos);
		if (c == ')') {
			pos++;
			return v;
		}
	}
	else {
		string s = "";
		while (true) {
			c = str.at(pos);
			if (c >= '0' && c <= '9') {
				s += c;
				pos++;
			}
			else {
				break;
			}
		}

		return atoi(s.c_str());
	}
	return 0;
}

CDBPropSet			cdbPropset;
CCommand <CAccessor<CMyClass>, CRowset> cCommand;
cdbPropset.AddProperty(DBPROP_CANSCROLLBACKWARDS, true);
cCommand.Open(m_pSessionManager->m_Session, csSQLQuery);
hr = cCommand.MoveFirst();
//insert some thing.
hr = cCommand.MovePrev();

Quote:

Input : arr[] : {1, 2, 3, 4, 5}
ranges[] = { {0, 2}, {0, 3} }
index : 1
Output : 3
Explanation : After first given rotation {0, 2}
arr[] = {3, 1, 2, 4, 5}
After second rotation {0, 3}
arr[] = {4, 3, 1, 2, 5}
After all rotations we have element 3 at given
index 1.

// CPP code to rotate an array
// and answer the index query
#include <bits/stdc++.h>
using namespace std;

// Function to compute the element at
// given index
int findElement(int arr[], int ranges[][2],
               int rotations, int index)
{
    for (int i = rotations - 1; i >= 0; i--) {

        // Range[left...right]
        int left = ranges[i][0];
        int right = ranges[i][1];

        // Rotation will not have any effect
        if (left <= index && right >= index) {
            if (index == left)
                index = right;
            else
                index--;
        }
    }

    // Returning new element
    return arr[index];
}

// Driver
int main()
{
    int arr[] = { 1, 2, 3, 4, 5 };

    // No. of rotations
    int rotations = 2;

    // Ranges according to 0-based indexing
    int ranges[rotations][2] = { { 0, 2 }, { 0, 3 } };

    int index = 1;

    cout << findElement(arr, ranges, rotations, index);

    return 0;

}

Quote:

and the authors logic: