1028.cpp

哈尔滨工业大学ACM 竞赛网上在线试题集锦的源代码

/*  This Code is Submitted by wywcgs for Problem 1028 on 2006-02-11 at 00:28:14 */ 
#include <cstdio>

const int MAX = 101;

int br, bi, bl;

bool find(int, int, int);

int main()
{
	int t, T, xr, xi;
	
	scanf("%d", &T);
	for(t = 0; t < T; t++) {
		scanf("%d %d %d %d", &xr, &xi, &br, &bi);
		bl = br * br + bi * bi;
		if(xr == 0 && xi == 0) printf("0\n");
		else if(!find(xr, xi, 0)) printf("The code cannot be decrypted.\n");
	}
	
	return 0;
}

bool find(int xr, int xi, int n)
{
	if(n == MAX) return false;
	else if(xr == 0 && xi == 0) return true;
	else {
		int i;
		for(i = 0; i*i < bl; i++) {
			int rxr = (xr - i) * br + xi * bi, rxi = xi * br - (xr - i) * bi;
			if(rxr % bl == 0 && rxi % bl == 0 && find(rxr/bl, rxi/bl, n+1))
				{ printf("%d%c", i, n == 0 ? '\n' : ','); return true; }
		}
		return false;
	}
}