Ecuatii

#include <cstdio>
#include <cstdlib>
#include <cstring>
#define Lmax 256
using namespace std;
char s[Lmax],s1[Lmax],s2[Lmax];
int n;
long nr1,nr2,nrx1,nrx2;

void Solve(char *s,long &nr,long &nrx)
{
    char *p,ss[Lmax];
    long v;
    int semn=1,L;
    strcpy(ss,s);
    p=strtok(ss,"+-");
    nr=0;
    nrx=0;
    while(p)
    {
        L=strlen(p);
        if(p[0]=='x')
            nrx+=semn;
        else
            if(p[L-1]=='x')
                p[L-1]=NULL,v=atol(p),nrx=nrx+semn*v;
            else
                v=atol(p),nr=nr+semn*v;
        if(s[p+L-ss]=='+')
            semn=1;
        else
            semn=-1;
        p=strtok(NULL,"+-");
    }
}

int main()
{
    FILE *f=fopen("ecuatii.in","r");
    FILE *g=fopen("ecuatii.out","w");
    int i;
    char *p;
    fscanf(f,"%d",&n);
    for(i=0;i<n;++i)
    {
        fscanf(f,"%s",s1);
        p=strchr(s1,'=');
        strcpy(s2,p+1);
        *p=NULL;
        Solve(s1,nr1,nrx1);
        Solve(s2,nr2,nrx2);
        if(nrx1==nrx2)
            if(nr1==nr2)
                fprintf(g,"infit\n");
            else
                fprintf(g,"imposibil\n");
        else
            fprintf(g,"%.4lf\n",((double)(nr2-nr1)/(nrx1-nrx2)));
    }
    fclose(f);
    fclose(g);
    return 0;
}