Wrong Answer.wrong answer On line 1 column 1, read (ASCII 0), expected x. 错误答案。错误答案在第1行第1列，读取（ASCII 0），应为x。

#include<bits/stdc++.h>
using namespace std;
int x,pl,uk,f = 1;
char s,v;
int main()
{
	freopen("t.txt","r",stdin);
	while(cin >> s)
	{
		if(s == '=') break;
		if(s == '-' || s == '+')
		{
			pl += x * f;
			x = 0,f = 1;
			if(s == '-') f = -1;
			continue;
		}
		if(s < '0' || s > '9')
		{
			v = s;
			uk += x * f;
			x = 0;
			continue;
		}
		x = x * 10 + s - 48;
	}
	pl += x * f;
	x = 0; 
	f = 1;
	while(cin >> s)
	{
		if(s == '-' || s == '+')
		{
			pl -= x * f;
			x = 0,f = 1;
			if(s == '-') f = -1;
			continue;
		}
		if(s < '0' || s > '9')
		{
			uk -= x * f;
			x = 0;
			continue;
		}
		x = x * 10 + s - 48;
	}
	pl -= x * f;
	double ans = -1.0 * pl / uk;
	if(ans == 0) printf("0.000\n");
	else printf("%c=%.3lf\n",v,ans);
	return 0;
}