6174问题

//--------------------C_Style----------------------

#include<stdio.h>
#include<string.h>
const int maxn = 3000;

int get_next(int n)
{
    char str[10];
    sprintf(str, "%d", n);        //将%d的n转换成字符串存入到str中
    int size = strlen(str);
    for(int ix = 1; ix != size; ++ix)        //降序
    {
        int key = str[ix], index = ix -1;
        for(; index >=0 && str[index] < key; --index)
            str[index+1] = str[index];
        str[index+1] = key;
    }
    int a = 0;
    sscanf(str, "%d", &a);        //将字符串str转换成%d，存入到a中
    int index = size-1;
    for(ix = 0; ix < size/2, index >= size/2; ++ix, --index)
    {
        int t;
        t = str[ix];
        str[ix] = str[index];
        str[index] = t;
    }
    int b = 0;
    sscanf(str, "%d", &b);
    return a-b;
}
int main()
{
    int n;
    scanf("%d", &n);
    printf("%d", n);
    while(get_next(n) !=n)
    {
        printf("->%d", get_next(n));
        n = get_next(n);
    }
    printf("->%d\n", n);
    return 0;
}

//------------------------------------C++_Style---------------------------------------------
#include<iostream>
#include<vector>
#include<sstream>
using namespace std;

int getnext(int n)
{
    string str;
    stringstream stream;
    stream << n;       //将n读入流stream中
    stream >> str;      //将n存入string对象中（相当于将整型转化为string）
    stream.clear();     //重置stream内部状态
    for(string::size_type i = 1; i != str.size(); ++i)      //升序排序，得到最小值
    {
        char key = str[i];
        string::size_type j = i-1;
        for(; j >= 0 && str[j] > key; --j)
            str[j+1] = str[j];
        str[j+1] = key;
    }
    stream.str("");     //清空stream对象
    stream << str;      //将string对象存入整型
    int min;
    stream >> min;      //将string转化为整型
    stream.clear();
    stream.str("");
    //倒置stream对象得到最大值
    for(string::size_type i = 0, j = str.size()-1; i < str.size()/2; ++i, --j)
    {
        char t;
        t = str[i];
        str[i] = str[j];
        str[j] = t;
    }
    stream << str;
    int max;
    stream >> max;  //转化成整型数
    return max - min;
}

int find(const vector<int> &ivec, int n)        //查找是否已存在
{
    for(vector<int>::size_type i = 0; i != ivec.size()-1; ++i)
        if(ivec[i] == n)
            return 1;
    return 0;
}
int main()
{
    int n;
    vector<int> ivec;
    while(cin >> n)
    {
        ivec.push_back(n);
        cout << n;
        while(!find(ivec, getnext(n)))
        {
            cout << "->" << getnext(n);
            ivec.push_back(getnext(n));
            n = getnext(n);
        }
    }
    return 0;
}