UVa 11507 - Bender B.Rodriguez...*(simulation,if-else)

Link:https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=27&page=show_problem&problem=2502
Sol:

#include <cstdio>
	using namespace std;
	bool change(char cur, char c1, char c2){
	if(cur == 'x' && c1 == '-') return true;
	if(cur == 'y' && c2 == 'y' && c1 == '+') return true;
	if(cur == 'z' && c2 == 'z' && c1 == '+') return true;
	return false;
	}
	int main(){
	int L;
	char s[3];
	while(true){
	scanf("%d",&L);
	if(L == 0) break;
	--L;
	int sign = 1;
	char c = 'x';
	for(int i = 0;i < L;++i){
	scanf("%s",s);
	if(s[0] == 'N') continue;
	if(change(c,s[0],s[1])) sign = -sign;
	if(c == 'x') c = s[1];
	else if(c == 'y' && s[1] == 'y') c = 'x';
	else if(c == 'z' && s[1] == 'z') c = 'x';
	}
	printf("%c%c\n",sign == 1? '+' : '-',c);
	}
	return 0;
	}