1937.cpp

这是哈尔滨工业大学acmOJ的源代码

/*  This Code is Submitted by wywcgs for Problem 1937 on 2005-10-07 at 13:36:24 */ 
#include <cstdio>
#include <cstring>

int main()
{
	long A[11][11], n, m;
	int i, j, k, c;
	bool app[10], printed;

	for(i = 0; i < 11; i++) {
		for(j = 0; j <= i; j++) {
			if(j == 0 || i == 1) {
				A[j][i] = 1;
			} else {
				A[j][i] = A[j-1][i] * (i - j + 1);
			}
		}
	}
	while(scanf("%ld", &n) == 1) {
		if(n == 0) {
			return 0;
		} else {
			memset(app, false, sizeof(app));
			for(k = 1; k < 11; k++) {
				if(n > 9 * A[k-1][9]) {
					n -= 9 * A[k-1][9];
				} else {
					break;
				}
			}
			printed = false;
			for(i = k; i > 0; i--) {
				if(n % A[i-1][9-k+i] == 0) {
					m = n / A[i-1][9-k+i];
					n = A[i-1][9-k+i];
				} else {
					m = n / A[i-1][9-k+i] + 1;
					n %= A[i-1][9-k+i];
				}
				c = 0;
				for(j = 0; j < 10; j++) {
					if(!app[j]) {
						if(j != 0) {
							c++;
						} else if(printed) {
							c++;
						}
					}
					if(c == m) {
						printf("%d", j);
						app[j] = true;
						printed = true;
						break;
					}
				}
			}
			putchar('\n');
		}
	}
	
 	return 0;
}