USACO 2.2.1Preface Numbering

题意：

给定整数N， 采用罗马数字的方式表达，统计每个罗马字符的个数，从小到大输出

解法：

枚举，统计每一个数字的字符数，然后输出

/*
ID: lsswxr1
PROG: preface
LANG: C++
*/
#include <iostream>
#include <vector>
#include <map>
#include <list>
#include <set>
#include <deque>
#include <stack>
#include <queue>
#include <algorithm>
#include <cmath>
#include <cctype>
#include <cstdio>
#include <iomanip>
#include <cmath>
#include <cstdio>
#include <string>
#include <cstring>
#include <fstream>
using namespace std;

#define USACO
#ifdef USACO
#define cin fin
#define cout fout
#endif
//////////////////////////////////////////////////////////////////////////
///宏定义
const int  INF = 1000000000;
const int MAXN = 40001;
const int maxn = MAXN;
///全局变量 和 函数
int N;
int counter[5000];
inline void cnt(int num, int tot)
{
    if (tot != 0)
    {
        if (tot == 9)
        {
            counter[num * 10] += 1;
            counter[num] += 1;
        }
        else if (tot >= 5)
        {
            int v = tot / 5;
            int c = tot % 5;
            counter[num * 5] += v;
            counter[num] += c;
        }
        else if (tot == 4)
        {
            counter[num] += 1;
            counter[num * 5] += 1;
        }
        else
        {
            counter[num] += tot;
        }
    }
}
int ans[] = {1, 5, 10, 50, 100, 500, 1000}; //一共7个
char ansChar[] = {'I', 'V', 'X', 'L', 'C', 'D', 'M'};
int main()
{

#ifdef USACO    
    ofstream fout ("preface.out");
    ifstream fin ("preface.in");
#endif   
    while (cin >> N)
    {
        memset(counter, 0, sizeof(counter));
        for (int i = 1; i <= N; i++)
        {
            int temp = i;
            int thousond = temp / 1000;
            if (thousond != 0)
            {
                counter[1000] += thousond;
            }
            temp -= thousond * 1000;
            int hundred = temp / 100;
            temp -= 100 * hundred;
            cnt(100, hundred);

            int ten = temp / 10;
            temp -= 10 * ten;
            cnt(10, ten);

            cnt(1, temp);            
        }
        for (int i = 0; i < 7; i++)
        {
            if (counter[ans[i]] == 0)
            {
                continue;
            }
            cout << ansChar[i] << " ";
            cout << counter[ans[i]];
            cout << endl;
        }
    }
    
    
    ///结束
    return 0;
}