Codeforces Round #305 (Div. 1), problem: (A) Mike and Frog,

Case炸了QAQ

#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <cmath>
#include <vector>
#include <map>
#include <set>
#include <utility>

using namespace std;

typedef long long int int64;

int64 get64(){
    int inp; scanf("%d", &inp);
    return inp;
}

int64 m;
void make(int64* lst, int64 x, int64 y, int64& r, int64& l, int64 st){
    lst[st] = 1;
    int64 step = 1;
    for(;;){
        st = (x*st + y)%m;
        step++;
        if(lst[st] != 0){
            l = lst[st]-1;
            r = step-lst[st];
            break;
        }
        lst[st] = step;
    }
    return;
}

int64 sp1[1000000] = {0}, sp2[1000000] = {0};

int64 inv(int64 a, int64 mm){
    for(int64 lx = 1;lx <= mm-1;lx++)
        if((a*lx)%mm == 1)
            return lx;
    return 0;
}

int main(){
    m = get64();
    int64 h1 = get64(), a1 = get64(), x1 = get64(), y1 = get64();
    int64 h2 = get64(), a2 = get64(), x2 = get64(), y2 = get64();
    int64 l1, l2, r1, r2;
    make(sp1, x1, y1, r1, l1, h1);
    make(sp2, x2, y2, r2, l2, h2);
    
    if(sp1[a1] == 0 or sp2[a2] == 0){ puts("-1"); return 0; }

    int64 la1 = sp1[a1], la2 = sp2[a2];
    int64 t1, t2;
    t1 = (la1 <= l1) ? 0:r1;
    t2 = (la2 <= l2) ? 0:r2;

    if(t1 == 0 and t2 == 0){ printf("%I64d\n", la1 == la2 ? (la1-1) : -1); return 0; }
    
    int64 gg = (t1 and t2) ? __gcd(t1, t2) : t1+t2;

    if((la1-la2)%gg != 0){ puts("-1"); return 0;}
    
    int64 dl = (la1-la2)/gg, d1 = t1/gg, d2 = t2/gg;    

    int64 cal = d2 ? (-inv(d1, d2)*dl)%d2 : (-dl);
    
    if(d2 == 0 and cal < 0){
        puts("-1");
        return 0;
    }
     
    if(cal < 0) cal += d2;
    while(d1*cal+dl<0) cal += d2;

    printf("%I64d\n", t1*cal+la1-1);

    return 0;
}