2368.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 2368 on 2006-09-22 at 16:29:38 */
#include <cstdio>
#include <cmath>
#include <cctype>
#include <algorithm>
using namespace std;

const int N = 256;

int coe, con, left;
char line[N];

void scan(char*&, int);
 
int main()
{
	int T;

	scanf("%d\n", &T);
	for(int t = 0; t < T; t++) {
		gets(line);
		char* p = line, ch  = *(p++);
		coe = con = 0; left = 1;
		int sign = 1;
		if(ch == '-') sign = -1;
		else p--; 
		scan(p, sign);
		while((ch = *(p++)) != 0) {
			switch(ch) {
			case '=': left = -1;
			case '+': sign = 1; break;
			case '-': sign = -1; break;
			}
			scan(p, sign);
		}
		if(coe == 0) {
			if(con == 0) printf("IDENTITY\n");
			else printf("IMPOSSIBLE\n");
		} else printf("%.0lf\n", floor(1.0*con/coe+1e-6));
	}
	
	return 0;
}

void scan(char*&p, int sign)
{
	int c = 1; sscanf(p, "%d", &c);
	if(*p == '+' || *p == '-') p++;
	while(isdigit(*p)) p++;
	char ch = *(p++);
	if(ch == 'x') coe += left*sign*c;
	else { p--; con -= left*sign*c; }
}