BZOJ 5418: [Noi2018]屠龙勇士 EXCRT+multiset

#include <set> 
#include <cstdio>     
#include <string>             
#include <algorithm>  
#define N 200000 
#define ll long long  
#define ull unsigned long long 
using namespace std;  
void setIO(string s) {
    string in=s+".in",out=s+".out"; 
    freopen(in.c_str(),"r",stdin); 
    // freopen(out.c_str(),"w",stdout); 
}  
int cas;    
multiset<ll>S;
multiset<ll>::iterator it;   
ll A[N],P[N],Power[N],reward[N]; 
ll mult(ll x,ll y,ll mod) {
    ll tmp=(long double)x/mod*y;   
    return ((ull)x*y-(ull)tmp*mod+mod)%mod; 
} 
ll qpow(ll base,ll k,ll mod) {
    ll tmp=1;
    for(;k;base=mult(base,base,mod),k>>=1) 
        if(k&1) 
            tmp=mult(tmp,base,mod); 
    return tmp;    
} 
ll exgcd(ll a,ll b,ll &x,ll &y) {
    if(!b) {
        x=1,y=0; 
        return a; 
    } 
    ll gcd=exgcd(b,a%b,x,y),tmp=x;   
    x=y,y=tmp-a/b*y;   
    return gcd; 
}       
void solve() { 
    S.clear();       
    ll ans,M,Max=0;
    int i,j,n,m,flag=0,nosol=0; 
    scanf("%d%d",&n,&m);   
    for(i=1;i<=n;++i) scanf("%lld",&A[i]);  
    for(i=1;i<=n;++i) scanf("%lld",&P[i]); 
    for(i=1;i<=n;++i) scanf("%lld",&reward[i]);   
    for(i=1;i<=m;++i) scanf("%lld",&Power[i]),S.insert(Power[i]);                    
    for(i=1;i<=n;++i) {    
        ll cur;  
        it=S.upper_bound(A[i]);     
        if(it!=S.begin()) it--;      
        cur=(*it);     
        S.erase(it);              
        S.insert(reward[i]);         
        Max=max(Max,A[i]%cur==0?A[i]/cur:A[i]/cur+1);      
        if(A[i]>P[i]) {
            flag=1; 
        }
        ll a,b,x,y,c,gcd; 
        a=cur,b=P[i],c=A[i];     
        gcd=exgcd(a,b,x,y),b=abs(b/gcd);         
        if(c%gcd) {
            nosol=1;       
            break;     
        }  
        x=(mult(x,c/gcd,b)+b)%b;                     // 当前这局的          
        if(i==1) ans=x,M=b;       
        else {
            ll curans=x,curM=b;   
            a=M,b=curM,c=curans-ans;     
            gcd=exgcd(a,b,x,y);   
            if(c%gcd) {
                nosol=1; 
                break; 
            }   
            b=abs(b/gcd);  
            x=(mult(x,c/gcd,b)+b)%b;    
            ans+=M*x;     
            M*=curM/__gcd(M,curM);    
            ans=(ans%M+M)%M;  
        }
    }               
    if(nosol) printf("-1\n"); 
    else printf("%lld\n",flag?Max:ans);       
}
int main() { 
    int i,j,T;
    // setIO("input");  
    scanf("%d",&T);                    
    for(cas=1;cas<=T;++cas) 
        solve();   
    return 0; 
}