1012.cpp

这是哈尔滨工业大学acmOJ的源代码

/*  This Code is Submitted by wywcgs for Problem 1012 on 2005-12-26 at 12:12:01 */ 
#include <cstdio>
#include <cstring>

const int MAX = 10240;
const int BEGIN = ' ';

bool parse(char*, int*);

int main()
{
	int E[MAX], Ex[MAX], C[MAX], K[MAX];
	char e[2*MAX], ex[2*MAX];
	int i;
	
	while(true) {
		if(!parse(gets(e), E)) break;
		if(!parse(gets(ex), Ex)) break;
		int n = strlen(e) / 2;
		K[0] = Ex[0] ^ BEGIN;
		for(i = 0; i < n; i++) {
			C[i] = K[i] ^ E[i];
			K[i+1] = C[i] ^ Ex[i+1];
		}
		for(i = 0; i <= n; i++) printf("%02X", K[i]);
		putchar('\n');
	}
	
	return 0;
}

bool parse(char* p, int* e)
{
	if(p == NULL) return false;
	else {
		int i, l = strlen(p) / 2;
		for(i = 0; i < l; i++) {
			sscanf(p, "%2X", &e[i]);
			p += 2;
		}
		return true;
	}
}