Problem C. Recycled Numbers

RecycledNumbers.cpp

/*************************************************************************
Author: logicmd
Created Time: 2012/7/24 17:43:17
File Name: RecycledNumbers.cpp
Description: 
************************************************************************/
#include <cassert>
#include <iostream>
#include <set>
#include <map>
#include <cstdio>
#include <string>

#include <utility>
#include <algorithm>

#define MAXT 50

using namespace std;
typedef pair<int, int> RNumSets;

int shift(int x)
{
    int len = 0, forestep = 1;
    for(int _x = x; _x > 0; _x /= 10)
    {
        len ++;
        forestep *= 10;
    }
    
    int last, fore, step = 1;

    for(int i = 0; i < len; i++)
    {
        step *= 10;
        last = x % step;
        fore = x / step;

        if(last != 0)
            break;
    }
    forestep /= step;
    return last * forestep + fore;
}

set< RNumSets > findRecycledNumbers(int lower, int higher)
{
    set< RNumSets > container;
    for(int x = lower; x <= higher; x++)
    {
        // if(container.find(x) != container.end());
        int y = shift(x);
        while(y != x)
        {
            if( y >= lower && y <= higher )
            {   
                container.insert(make_pair(x, y));
                container.insert(make_pair(y, x));
                break;
            }
            y = shift(y);
        }
    }
    // 
    return container;
}

void getRecycledNumbers(set< RNumSets > container)
{
    cout << "Recycled Numbers: " << endl;
    for( set< RNumSets >::iterator it = container.begin(); it != container.end(); it++ )
    {
        cout << "(" << (*it).first << ", " << (*it).second << ")" << "\t";
        container.erase( container.find( make_pair((*it).second, (*it).first)) );
    }
    cout << endl;
}

int main()
{
    // cout << shift(123) << endl;
    // cout << shift(987213) << endl;
    // cout << shift(12) << endl;
    // cout << shift(1002) << endl;
    // cout << shift(2100) << endl;
    // cout << shift(909098) << endl;
    // cout << shift(989090) << endl;
    int T, result[MAXT];
    cin >> T;
    for(int ti = 0; ti < T; ti ++)
    {
        
        int low, high;
        cin >> low >> high;
        set< RNumSets > allR = findRecycledNumbers(low, high);
        assert(allR.size() % 2 == 0);
        result[ti] = allR.size() / 2;
        // getRecycledNumbers(allR);
    }

    for(int ti = 0; ti < T; ti ++)
    {
        cout << "Case #" << ti + 1 << ": " << result[ti] << endl;
    }

    // system("PAUSE");
    return 0;
}