USACO 2.2 Preface Numbering (模拟)

#include <stdio.h>
#define DEBUG 1
#define TESTCASES 8

int pages;
char *RomanNumbers= "IVXLCDM";
//pattern表示一位（个，十，百，千）上的罗马数字的字母表示模式，采用012表示为了方便跟RomanNumbers的下标关联
char *pattern[10] = {"-1", "0", "00", "000", "01", "1", "10", "100", "1000", "02"};
//count[i]表示代表罗马数字的字母RomanNumbers[i]的统计结果
int count[7];

int main(){
#if DEBUG
	int testCase;
	for (testCase = 1; testCase <= TESTCASES; testCase++){
		char inputFileName[20] = "inputx.txt";
		inputFileName[5] = '1' +  (testCase - 1);
		freopen(inputFileName, "r", stdin);
		printf("\n#%d\n", testCase);
#endif

	int RomanIndex;
	for (RomanIndex = 0; RomanIndex < 7; RomanIndex++)
		count[RomanIndex] = 0;

	scanf("%d", &pages);
	int num;
	for (num = 1; num <= pages; num++){
		int divisor= 1000;
		RomanIndex = 6;
		int tempNum = num;
		while ( tempNum != 0){
			int digit = tempNum / divisor;
			if (digit != 0){
				int i;
				for (i = 0; pattern[digit][i] != '\0'; i++)
					count[ RomanIndex + pattern[digit][i] - '0' ]++;
			}
			tempNum %= divisor;
			divisor /= 10;
			RomanIndex -= 2;
		}
	}
	
	for (RomanIndex = 0; RomanIndex < 7; RomanIndex++)
		if (count[RomanIndex] != 0)
		printf("%c %d\n", RomanNumbers[RomanIndex], count[RomanIndex]);

#if DEBUG
	}
#endif
	return 0;
}